Definition
Strictly speaking, a transistor generally refers to all single components based on semiconductor materials, including diodes (two-terminal), triodes, and field effects made of various semiconductor materials. Tube, thyristor (the latter three are all three-terminal), etc. Transistors are sometimes referred to as transistors.
Three-terminal transistors are mainly divided into two categories: bipolar transistors (BJT) and field effect transistors (FET, unipolar). The transistor has three poles (terminals); the three poles (terminals) of the bipolar transistor are the Emitter, Base and Collector composed of N-type and P-type semiconductors respectively; field; The three poles (terminals) of the effect transistor are the source (Source), the gate (Gate) and the drain (Drain).
Because the transistor has three electrodes, there are also three ways to use it, namely emitter grounding (also known as common emitter amplification, CE configuration), base grounding (also known as common base amplification, CB group State) and collector grounding (also known as collective amplification, CC configuration, emitter follower).
Introduction
Intel 3D Transistor Technology (16 photos)
Transistor is a semiconductor device, commonly used in amplifiers or electronically controlled switches. Transistors are the basic building blocks that regulate the operation of computers, mobile phones, and all other modern electronic circuits.Because of its fast response speed and high accuracy, transistors can be used for a variety of digital and analog functions, including amplification, switching, voltage stabilization, signal modulation and oscillators. Transistors can be packaged individually or in a very small area that can hold 100 million or more transistors as part of an integrated circuit.
History
In December 1947, a research team composed of Shockley, Barding, and Bratton of Bell Labs in the United States developed a point-contact germanium transistor. The advent of the transistor was a major invention in the 20th century and a precursor to the revolution in microelectronics. After the appearance of the transistor, people can use a small, low-power electronic device to replace the large-scale and high-power electronic tube. The invention of the transistor sounded the clarion call for the subsequent birth of integrated circuits. In the first 10 years of the 20th century, communication systems have begun to use semiconductor materials. In the first half of the 20th century, mineral radios, which were widely popular among radio enthusiasts, used ore as a semiconductor material for detection. The electrical properties of semiconductors are also used in telephone systems.
The invention of the transistor can be traced back to 1929, when engineer Lilian Feld had already obtained a patent for a transistor. However, limited to the technological level at the time, the materials used to manufacture such devices were not sufficiently pure, making it impossible to manufacture such transistors.
Because of the unsatisfactory effect of the electronic tube processing high-frequency signals, people try to improve the ore whisker type detector used in the mineral radio. In this kind of detector, there is a metal wire (thin as a hair and forming a detection contact) that is in contact with the surface of the ore (semiconductor), which can not only allow the signal current to flow in one direction, but also prevent the signal current from going in the opposite direction. Direction flows. On the eve of the outbreak of the Second World War, Bell Laboratories was looking for a detection material with better performance than the galena crystals used earlier, and found that germanium crystals doped with a very small amount of impurities not only performed better than ore crystals, but also In some respects it is better than the tube rectifier.
During the Second World War, many laboratories made a lot of achievements in the manufacturing and theoretical research of silicon and germanium materials, which laid the foundation for the invention of the transistor.
In order to overcome the limitations of electron tubes, after the end of World War II, Bell Laboratories stepped up its basic research on solid-state electronic devices. Shockley and others decided to concentrate on researching semiconductor materials such as silicon and germanium and discuss the possibility of using semiconductor materials to make amplifier devices.
In the fall of 1945, Bell Labs established a semiconductor research group headed by Shockley, with members such as Bratton, Barding and others. Bratton began working in this laboratory as early as 1929, has been engaged in semiconductor research for a long time, and has accumulated rich experience. After a series of experiments and observations, they gradually realized the cause of the current amplification effect in semiconductors. Bratton discovered that an electrode was connected to the bottom surface of the germanium sheet, a thin needle was inserted on the other side and the current was passed through, and then the other thin needle was as close to it as possible, and a weak current was passed through it, which would make the original The current changes greatly. A small amount of change in the weak current will have a great impact on the other current, which is the "amplification" effect.
Braton and others also figured out effective ways to achieve this amplification effect. They input a weak signal between the emitter and the base, and amplify it into a strong signal at the output between the collector and the base. In modern electronic products, the amplification effect of the above-mentioned transistor is widely used.
The magnification of the solid device originally made by Bartin and Bratton is about 50. Soon after, they used two very close (0.05 mm apart) whisker contacts instead of gold foil contacts to create a "point contact transistor." In December 1947, the world's earliest practical semiconductor device finally came out. In the first test, it can amplify the audio signal by 100 times. Its shape is shorter than a matchstick, but thicker.
When naming this device, Bratton thought of its resistance transformation characteristics, that is, it works by a transfer current from "low resistance input" to "high resistance output". So it was named trans-resistor (conversion resistance), later abbreviated as transistor, the Chinese translation is transistor.
Due to the complex manufacturing process of point contact transistors, many products have failed. It also has shortcomings such as high noise, difficult to control when the power is high, and narrow application range. In order to overcome these shortcomings, Shockley proposed a bold idea of replacing metal semiconductor contacts with a "rectifier junction". The semiconductor research team put forward the working principle of this kind of semiconductor device.
In 1950, the first "PN junction transistor" came out, and its performance was exactly the same as Shockley's original vision. Most of today's transistors are still such PN junction transistors. (The so-called PN junction is the junction of P-type and N-type. P-type multiple holes. N-type multiple electrons.)
In 1956, Shockley, Barding, and Bratton were invented The transistor also won the Nobel Prize in Physics.
Development of transistors
1) Vacuum triode
In February 1939, Bell Labs made a great discovery, the birth of silicon p_n junction. In 1942, a student named SeymourBenzer in the research group led by Purdue University Lark_Horovitz discovered that germanium single crystal has excellent rectification performance that other semiconductors do not have. These two discoveries met the requirements of the U.S. government and laid the groundwork for the subsequent invention of the transistor.
2) Point-contact transistors
At the end of World War II in 1945, the point-contact transistors invented by Shockley and others became the forerunner of the human microelectronics revolution. To this end, Shockley submitted Bell's first patent application for a transistor. In the end, the first transistor patent was authorized.
3) Bipolar and unipolar transistors
On the basis of bipolar transistors, Shockley further proposed the concept of unipolar junction transistors in 1952, which is today The so-called junction transistor. Its structure is similar to pnp or npn bipolar transistors, but there is a depletion layer at the interface of p_n material to form a rectifying contact between the gate and the source and drain conductive channels. At the same time, the semiconductors at both ends are used as gates. Adjust the current between source and drain through the gate.
4) Silicon transistors
Fairchild Semiconductor has grown from a company of several people to a large company with 12,000 employees.
5) Integrated circuits
After the invention of silicon transistors in 1954, the huge application prospects of transistors have become more and more obvious. Scientists’ next goal is how to further efficiently connect transistors, wires and other devices.
6) Field effect transistor and MOS tube
In 1961, MOS tube was born. In 1962, Stanley, Heiman and Hofstein, who worked in the RCA Device Integration Research Group, found that the conductive band, high-resistance channel region and oxide insulating layer formed on the Si substrate can be constructed by diffusion and thermal oxidation to construct a transistor, that is, MOS. Tube .
7) Microprocessor (CPU)
At the beginning of its establishment, Intel Corporation still focused on the memory stick. Hoff integrated all the functions of the central processing unit on a chip, plus memory; this is the world's first microprocessor-4004 (1971). The birth of 4004 marked the beginning of an era, and then Intel was out of control in the research of microprocessors, leading the way.
In 1989, Intel introduced the 80486 processor. In 1993, Intel successfully developed a new generation of processors, originally according to the usual naming rule is 80586. In 1995, Intel launched Pentium_Pro. In 1997, Intel released the Pentium II processor. Intel released the Pentium III processor in 1999. The Pentium4 processor was released in 2000.
Milestone
December 16, 1947: William Shockley, John Bardeen, and Walter Brattain successfully experiment at Bell Chamber made the first transistor.
In 1950: William Shao Kelei developed the Bipolar Junction Transistor, which is the current standard transistor.
1953: The first commercial device using transistors was put on the market, namely hearing aids.
October 18, 1954: The first transistor radio RegencyTR1 was put on the market, containing only 4 germanium transistors.
April 25, 1961: The first integrated circuit patent was granted to Robert Noyce. The original transistors are sufficient for radios and phones, but new electronic devices require smaller transistors, namely integrated circuits.
1965: Moore's Law was born. At that time, Gordon Moore predicted that the number of transistors on a chip would double approximately every 18 months in the future (still basically applicable), and Moore's Law was published in an article in Electronics Magazine.
July 1968: Robert Noyce and Gordon Moore resigned from Fairchild (Fairchild) Semiconductor Corporation and founded a new enterprise, Intel Corporation, whose English name is "Integrated Electronics". Abbreviation for "integrated electronics".
1969: Intel successfully developed the first PMOS silicon gate transistor technology. These transistors continue to use the traditional silicon dioxide gate dielectric, but introduce a new polysilicon gate electrode.
1971: Intel released its first microprocessor 4004. The 4004 specification is 1/8 inch x 1/16 inch, contains only more than 2,000 transistors, and is produced using Intel’s 10-micron PMOS technology.
In 1972, Intel released the first 8-bit processor 8008.
In 1978, Intel released the first 16-bit processor 8086. Contains 29,000 transistors.
1978: Intel markedly sold the Intel 8088 microprocessor to IBM's new personal computer division, arming the central brain of IBM's new product IBMPC. The 16-bit 8088 processor is an improved version of the 8086, contains 29,000 transistors, and runs at 5MHz, 8MHz and 10MHz. The success of the 8088 pushed Intel into the FORTUNE 500 list, and the "FORTUNE" magazine rated Intel as one of the "Business Triumphsofthe Seventies".
1982: 286 microprocessor (full name 80286, meaning "second generation 8086") was launched, and the concept of instruction set was put forward, that is, the current x86 instruction set, which can be run by Intel’s previous generation of products. All software written. The 286 processor uses 13,400 transistors and runs at 6MHz, 8MHz, 10MHz, and 12.5MHz.
1985: Intel 386 microprocessor came out, containing 275,000 transistors, more than 100 times the number of the original 4004 transistors. 386 is a 32-bit chip with multitasking capabilities, that is, it can run multiple programs at the same time.
1993: Intel · Pentium · processor came out, containing 3 million transistors, using Intel's 0.8 micron process technology.
February 1999: Intel released the Pentium III processor. The Pentium III is 1x1 square silicon, containing 9.5 million transistors, and is produced using Intel's 0.25-micron process technology.
January 2002: Intel Pentium 4 processor was launched, high-performance desktop desktop computers can achieve 2.2 billion cycles per second. It is produced using Intel’s 0.13-micron process technology and contains 55 million transistors.
August 13, 2002: Intel revealed several technological breakthroughs in 90-nanometer process technology, including high-performance, low-power transistors, strained silicon, high-speed copper connectors and new low-k dielectric materials. This is the industry's first use of strained silicon in production.
March 12, 2003: The Intel Centrino mobile technology platform for notebooks was born, including Intel’s latest mobile processor "Intel Pentium M Processor". The processor is based on a new mobile-optimized micro-architecture, produced using Intel’s 0.13-micron process technology, and contains 77 million transistors.
May 26, 2005: Intel’s first mainstream dual-core processor "Intel Pentium D Processor" was born, containing 230 million transistors and produced using Intel’s leading 90-nanometer process technology.
200July 18, 2006: Intel’s Itanium 2 dual-core processor was released, using the world’s most complex product design, containing 270 million transistors. The processor is produced using Intel’s 90-nanometer process technology.
July 27, 2006: Intel Core 2 Duo processor was born. The processor contains more than 290 million transistors and is produced in several of the world's most advanced laboratories using Intel's 65-nanometer process technology.
September 26, 2006: Intel announced that more than 15 45-nanometer process products are being developed for the desktop, notebook and enterprise computing markets. The research and development code Penryn is derived from the Intel Core microarchitecture Out. January 8, 2007: In order to expand the sales of quad-core PCs to mainstream buyers, Intel released the 65-nanometer Intel Core 2 quad-core processor for desktop computers and two other quad-core server processors. The Intel Core 2 quad-core processor contains more than 580 million transistors.
January 29, 2007: Intel announced the use of breakthrough transistor materials, namely high-k gate dielectrics and metal gates. Intel will use these materials to build insulation in the company's next-generation processors-Intel Core 2 Duo, Intel Core 2 quad-core processors, and Intel Xeon series multi-core processors with hundreds of millions of 45-nanometer transistors or tiny switches. "Wall" and opening and closing "doors", developed code Penryn. In November 2010, NVIDIA released a new GF110 core, containing 3 billion transistors, manufactured using an advanced 40-nanometer process. May 05, 2011: Intel successfully developed the world's first 3D transistor called tri-Gate. In addition to Intel's application of 3D transistors to the 22nm process, Samsung, GlobalFoundries, TSMC and UMC all plan to apply 3D transistor technology similar to Intel to the 14nm node.
Superiority
Compared with the electron tube, the transistor has many advantages:
The components are not consumed
No matter how good the electron tube is, Both will gradually deteriorate due to changes in cathode atoms and chronic air leakage. Due to technical reasons, the same problem existed at the beginning of the production of transistors. With the advancement of material production and various improvements, the life span of transistors is generally 100 to 1000 times longer than that of electron tubes.
The power consumption is very small
It is only one-tenth or one-tenth of the electron tube. It does not need to heat the filament to generate free electrons like an electron tube. A transistor radio can be listened to for six months a year with only a few dry batteries, which is difficult for a tube radio.
No need to warm up
It works as soon as it is turned on. For example, a transistor radio will ring as soon as it is turned on, and a picture will appear quickly when a transistor TV is turned on. Electronic tube equipment cannot do this. After powering on, wait for a while to hear the sound and see the picture. Obviously, transistors are very advantageous in military, measurement, and recording.
Strong and reliable
100 times more reliable than electronic tubes, shock and vibration resistance, which are unmatched by electronic tubes. In addition, the volume of the transistor is only one-tenth to one-hundredth of that of an electron tube, and it emits little heat. It can be used to design small, complex, and reliable circuits. Although the manufacturing process of the transistor is precise, the process is simple and convenient, which is conducive to improving the mounting density of the components.
Importance
Transistor, whose real name is a semiconductor transistor, is a semiconductor device with two PN junctions inside and three lead-out electrodes on the outside. It has the functions of amplifying and switching electric signals, and it has a wide range of applications. Both the input stage and the output stage use transistor logic circuits, called transistor-transistor logic circuits, which are referred to as TTL circuits in books and practical applications. It belongs to a type of semiconductor integrated circuit, among which TTL NAND gates are the most commonly used. The TTL NAND gate is a circuit system composed of several transistors and resistance elements, which is manufactured on a small silicon chip and packaged as an independent element. Transistor is one of the most widely used devices in semiconductor transistors. It is represented by "V" or "VT" (old text symbols are "Q", "GB", etc.) in the circuit.
The transistor is one of the most critical components of modern electrical appliances. The transistor can be used on a large scale because it can be mass produced at a very low unit cost.
At present, millions of single transistors are still in use, and most of them are diodes|-{A|zh-cn: diodes; zh-tw: diodes}-, Resistors and capacitors are assembled together on a microchip (chip) to make a complete circuit. Analog or digital or both are integrated on the same chip. The cost of designing and developing a complex chip is quite high, but when it is produced, the cost of designing and developing the chip is shared among millions of chips, so the cost of each chip in the market is usually not very high. expensive. A logic gate contains 20 transistors, and in 2005 an advanced microprocessor used 289 million transistors.
Especially after the importance of transistors in military planning and astronautics has become increasingly apparent, countries around the world have launched fierce competition in order to compete for a superior position in the electronic field. In order to realize the miniaturization of electronic equipment, people have given huge financial aid to the electronics industry at any cost.
Since Fleming invented the vacuum diode in 1904 and De Forest invented the vacuum triode in 1906, electronics has developed rapidly as an emerging discipline. But the real progress of electronics by leaps and bounds should have begun after the invention of the transistor. Especially the emergence of PN junction transistors opened up a new era of electronic devices and caused a revolution in electronic technology. In just over ten years, the emerging transistor industry, with invincible ambition and unscrupulous aura of young people, quickly replaced the position that the electron tube industry had achieved through years of hard work, and became the vanguard in the field of electronic technology. .
Classification
Materials
According to the semiconductor materials used in transistors, it can be divided into silicon material transistors and germanium material transistors. According to the polarity of the transistor, it can be divided into germanium NPN transistor, germanium PNP transistor, silicon NPN transistor and silicon PNP transistor.
Process
Transistors can be divided into diffusion transistors, alloy transistors and planar transistors according to their structure and manufacturing process.
Current capacity
Transistors can be divided into low-power transistors, medium-power transistors and high-power transistors according to current capacity.
Operating frequency
Transistors can be divided into low-frequency transistors, high-frequency transistors and ultra-high-frequency transistors according to their operating frequency.
Package structure
Transistors can be divided into metal package (gold seal for short) transistors, plastic package (plastic package for short) transistors, glass package (glass seal for short) transistors, Surface mount (chip) transistors and ceramic packaged transistors, etc. There are various package shapes.
According to function and purpose
Transistors can be divided into low noise amplifier transistors, medium and high frequency amplifier transistors, low frequency amplifier transistors, switching transistors, Darlington transistors, high reverse Voltage transistors, band-resistance transistors, damping transistors, microwave transistors, phototransistors and magneto-sensitive transistors, and many other types.
Type
Semiconductor transistor
It is a semiconductor device with two PN junctions inside and three lead electrodes outside. It has the functions of amplifying and switching electric signals, and it has a wide range of applications. Both the input stage and the output stage use transistor logic circuits, called transistor-transistor logic circuits, which are referred to as TTL circuits in books and practical applications. It belongs to a type of semiconductor integrated circuit, among which TTL NAND gates are the most commonly used. The TTL NAND gate is a circuit system composed of several transistors and resistance elements, which is manufactured on a small silicon chip and packaged as an independent element. Semiconductor transistors are one of the most widely used devices in circuits. They are represented by "V" or "VT" (the old text symbols are "Q", "GB", etc.) in the circuit.
Semiconductor transistors are mainly divided into two categories: bipolar transistors (BJT) and field effect transistors (FET). The transistor has three poles; the three poles of the bipolar transistor are composed of N-type and P-type emitter (Emitter), base (Base) and collector (Collector); the three poles of the field effect transistor are respectively Source, Gate and Drain. Because transistors have three polarities, there are also three ways to use them, namely emitter grounding (also known as common-emitter amplification, CE configuration), base grounding, and collector grounding. The most common use should be signal amplification, followed by impedance matching, signal conversion... etc. Transistors are very important components in circuits, and many precision components are mainly made of transistors.
The transistor's turn-on transistor is in the amplified state or the on-off state depends on the DC bias applied to the base of the transistor. With this current change, the working state of the transistor changes from the cut-off zone-linear zone-saturation zone. If the transistor Ib (DC bias point) is constant, the transistor works in the linear region. At this time, the Ic current changes only with the Ib AC signal. Ib continues to rise and the transistor enters a saturated state. At this time, the Ic of the transistor does not change. Change again, the triode will work in the on-off state.
If the transistor is not applied with DC bias, the base of the transmitter is positive for the emitter when the AC sinusoidal signal inputted in the amplifying circuit is positive, because the emitter junction is a reverse voltage, at this time There is no base current and collector current. At this time, the change of the collector current is opposite to that of the base. In the negative half cycle of the input voltage, the emitter potential is positive with respect to the base potential. At this time, since the emitter applies a positive voltage, Only when the base and collector currents pass, the collector current changes in the same phase as the base. When the transistor is not biased by DC, the transistor be junction and the ce junction are turned on, and the transistor amplifier circuit will only have half of the wave output, which will cause serious Distortion.
The low cost, flexibility, and reliability of the transistor make it a general-purpose device for non-mechanical tasks, such as digital computing. In terms of controlling electrical appliances and machinery, transistor circuits are also replacing electrical equipment, because it is generally cheaper and more effective, using only standard integrated circuits and writing computer programs to complete the same mechanical tasks, using electronic control instead of designing a Equivalent mechanical control.
Because of the low cost of transistors and later the wave of electronic computers and digital information has arrived. As computers provide the ability to quickly find, classify and process digital information, more and more energy has been invested in the digitization of information. Many of today's media are published in electronic form, and finally transformed and presented in analog form through computers. The areas affected by the digital revolution include television, radio and newspapers.
Power Transistor
According to the English GiantTransistor, a power transistor is literally translated as a giant transistor. It is a bipolar junction transistor (BipolarJunctionTransistor—BJT) that can withstand high voltage and high current. So sometimes It is called PowerBJT; its characteristics are: high withstand voltage, large current, good switching characteristics, but the driving circuit is complex, and the driving power is large; the working principle of GTR and ordinary bipolar junction transistor is the same.
Phototransistor
Phototransistor is an optoelectronic device composed of three-terminal devices such as bipolar transistors or field effect transistors. Light is absorbed in the active area of this type of device to generate photo-generated carriers, which generate photocurrent gain through the internal electrical amplifying mechanism. The phototransistor works with three terminals, so it is easy to realize electric control or electric synchronization. The material used in phototransistors is usually gallium arsenide (GaAs), which is mainly divided into bipolar phototransistors, field-effect phototransistors and related devices. Bipolar phototransistors usually have high gain, but not too fast. For GaAs-GaAlAs, the amplification factor can be greater than 1000, and the response time is greater than nanoseconds. It is often used for photodetectors and can also be used for optical amplification. The field-effect phototransistor has a fast response speed (about 50 picoseconds), but the disadvantage is that the photosensitive area is small and the gain is small (the amplification factor can be greater than 10), and it is often used as an extremely high-speed photodetector. Related to this, there are many other planar optoelectronic devices, all of which are characterized by fast speed (response time of tens of picoseconds) and suitable for integration. Such devices are expected to be used in optoelectronic integration.
Bipolar transistor
Bipolar transistor (bipolartransistor) refers to a type of transistor that is very commonly used in audio circuits. Bipolar is derived from the relationship between current flow in two semiconductor materials. Bipolar transistors can be classified into NPN type or PNP type according to the polarity of the operating voltage.
Bipolar junction
The meaning of "bipolar" means that both electron and hole carriers participate in movement at the same time when it works. Bipolar junction transistor (BipolarJunctionTransistor—BJT) is also called a semiconductor transistor. It is a device that combines two PN junctions through a certain process. It has two combined structures, PNP and NPN; three poles are drawn from the outside: collector , The emitter and the base, the collector is drawn from the collector area, the emitter is drawn from the emitter, and the base is drawn from the base (the base is in the middle); BJT has an amplifying effect, and it is important to rely on its emitter current to pass through the base. In order to ensure this transmission process, the internal conditions must be met on the one hand, that is, the impurity concentration of the emitter region must be far greater than the impurity concentration of the base region, and the thickness of the base region must be small. Meet the external conditions, that is, the transmitting junction must be forward biased (plus forward voltage), and the collector junction must be reverse biased; there are many types of BJTs, according to frequency, there are high-frequency tubes and low-frequency tubes, and according to power, there are small, Medium and high-power tubes, according to semiconductor materials, include silicon tubes and germanium tubes, etc.; the amplifying circuit forms they constitute include: common emitter, common base and common collector amplifying circuits.
Field Effect Transistor
The meaning of "field effect" is that the working principle of this kind of transistor is based on the electric field effect of semiconductors.
Field-effect transistor (fieldeffecttransistor) is a transistor that uses the principle of field-effect, and is referred to as FET in English. Field effect transistors include two main types: Junction FET (JunctionFET, abbreviated as JFET) and Metal-Oxide Semiconductor FET (Metal-Oxide Semiconductor FET, abbreviated as MOS-FET). Different from BJTHowever, FETs are only conducted by one type of carrier (majority carriers), so they are also called unipolar transistors. It is a voltage-controlled semiconductor device, which has the advantages of high input resistance, low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown, and wide safe working area.
Field effect is to change the direction or size of the electric field applied perpendicular to the surface of the semiconductor to control the density or type of majority carriers in the semiconductor conductive layer (channel). It is the current in the channel modulated by the voltage, and its working current is transported by the majority carriers in the semiconductor. This type of transistor in which only one polarity carrier participates in conduction is also called a unipolar transistor. Compared with bipolar transistors, field effect transistors have the characteristics of high input impedance, low noise, high limit frequency, low power consumption, simple manufacturing process, and good temperature characteristics. They are widely used in various amplifying circuits, digital circuits and microwave circuits. Wait. The metal 0-oxide-semiconductor field effect transistor (MOSFET) based on silicon material and the Schottky barrier gate field effect transistor (MESFET) based on gallium arsenide material are the two most important field effect transistors. They are the basic devices of MOS large-scale integrated circuits and MES ultra-high-speed integrated circuits.
Static induction
The static induction transistor SIT (StaticInductionTransistor) was born in 1970 and is actually a junction field effect transistor. By changing the horizontal conductive structure of the low-power SIT device used for information processing to the vertical conductive structure, a high-power SIT device can be made. SIT is a multi-sub-conducting device. Its operating frequency is equivalent to or even higher than that of power MOSFET, and its power capacity is also larger than that of power MOSFET. Therefore, it is suitable for high-frequency and high-power applications. It has been used in radar communication equipment, ultrasonic power Some professional fields such as amplification, pulse power amplification and high-frequency induction heating have been widely used.
But the SIT is turned on when no signal is applied to the gate, and it is turned off when the gate is negatively biased. This is called a normal conduction device and it is not convenient to use. In addition, the on-state resistance of SIT is relatively large, which makes the on-state loss also large, so SIT has not been widely used in most power electronic equipment.
Single-electron transistor
A transistor that can record signals with one or a small amount of electrons. With the development of semiconductor etching technology and technology, the integration of large-scale integrated circuits is getting higher and higher. Take Dynamic Random Access Memory (DRAM) as an example. Its integration is increasing at a rate of almost four times every two years. It is expected that single-electron transistors will be the ultimate goal. At present, the general memory contains 200,000 electrons in each storage element, while the single-electron transistor contains only one or a small amount of electrons in each storage element. Therefore, it will greatly reduce power consumption and improve the integration of integrated circuits. In 1989, J.H.F.Scott-Thomas and others discovered the phenomenon of Coulomb obstruction in experiments. On the two-dimensional electron gas formed by the modulated-doped heterojunction interface, a metal electrode with a small area is made, so that a quantum dot is formed in the two-dimensional electron gas, which can only hold a small amount of electrons, which is its capacitance Small, less than one? F (10~15 farads). When a voltage is applied, if the change in the voltage causes the charge in the quantum dot to change by less than an electron's charge, no current will flow. Until the voltage is increased to cause a change in the charge of an electron, no current flows. Therefore, the current-voltage relationship is not the usual linear relationship, but a step-shaped relationship. For the first time in history, this experiment realized the manual control of the movement of an electron, which provided an experimental basis for the manufacture of single-electron transistors. In order to increase the operating temperature of single-electron transistors, the size of quantum dots must be less than 10 nanometers. Currently, laboratories around the world are thinking of various ways to solve this problem. Some laboratories claim that they have produced single-electron transistors that work at room temperature, and they have observed stepped current-voltage curves formed by electron transport, but they are still far from practical.
IGBT
Insulate-GateBipolarTransistor-IGBT combines the advantages of power transistors (GiantTransistor-GTR) and power field effect transistors (PowerMOSFET). Features and applications are very wide; IGBT is also a three-terminal device: gate, collector and emitter.
Main parameters
The main parameters of the transistor include current amplification factor, power dissipation, frequency characteristics, maximum collector current, maximum reverse voltage, reverse current, etc.
Amplification factor
The DC current amplification factor is also called the static current amplification factor or the DC amplification factor, which refers to the transistor collector current IC and the base current when the static signal input is unchanged. The ratio of IB is generally expressed by hFE or β.
AC amplification factor
The AC amplification factor, that is, the AC current amplification factor and the dynamic current amplification factor, refers to the change in the collector current of the transistor △IC and the base in the AC state. The ratio of pole current change △IB is generally expressed by hfe or β.
hFE or β are both different and closely related. The two parameter values are closer at low frequencies, but there are some differences at high frequencies.
Dissipation power
The dissipation power is also called the maximum allowable collector dissipation power PCM, which refers to the maximum collector dissipation power when the transistor parameter changes do not exceed the specified allowable value.
The power dissipation is closely related to the maximum allowable junction temperature of the transistor and the maximum collector current. When the transistor is in use, its actual power consumption is not allowed to exceed the PCM value, otherwise the transistor will be damaged due to overload.
Usually, transistors that dissipate PCM less than 1W are called low-power transistors, transistors with PCM equal to or greater than 1W and less than 5W are called mid-power transistors, and transistors with PCM equal to or greater than 5W are called low-power transistors. High-power transistors.
Characteristic frequency fT When the operating frequency of the transistor exceeds the cut-off frequency fβ or fα, the current amplification factor β value will decrease as the frequency increases. The characteristic frequency refers to the operating frequency of the transistor when the β value drops to 1.
Usually, transistors with characteristic frequency fT less than or equal to 3MHZ are called low frequency tubes, transistors with fT greater than or equal to 30MHZ are called high frequency tubes, and transistors with fT greater than 3MHZ and less than 30MHZ are called intermediate frequency tubes. .
The highest frequency fM
The highest oscillation frequency refers to the frequency at which the power gain of the transistor drops to 1.
Generally, the highest oscillation frequency of a high-frequency transistor is lower than the common base cutoff frequency fα, and the characteristic frequency fT is higher than the common base cutoff frequency fα and lower than the common collector cutoff frequency fβ.
Maximum Current
The maximum collector current (ICM) refers to the maximum current allowed by the collector of the transistor. When the collector current IC of the transistor exceeds ICM, the β value and other parameters of the transistor will change significantly, which will affect its normal operation and even be damaged.
Maximum reverse voltage
Maximum reverse voltage refers to the maximum operating voltage allowed by the transistor during operation. It includes collector-emitter reverse breakdown voltage, collector-base reverse breakdown voltage and emitter-base reverse breakdown voltage.
Collector-collector reverse breakdown voltage
This voltage refers to the difference between the collector and emitter of the transistor when the base of the transistor is open. The maximum allowable reverse voltage between time, generally expressed by VCEO or BVCEO.
Base-base reverse breakdown voltage
This voltage refers to the difference between the collector and base of the transistor when the emitter of the transistor is open. The maximum allowable reverse voltage between VCBO or BVCBO.
Emitter-emitter reverse breakdown voltage
This voltage refers to when the collector of the transistor is open, its emitter and base The maximum allowable reverse voltage between and, expressed with VEBO or BVEBO.
The reverse current between the collector and the base ICBO
ICBO is also called the collector junction reverse leakage current, which refers to the When the emitter is open, the reverse current between the collector and the base. ICBO is more sensitive to temperature. The smaller the value, the better the temperature characteristics of the transistor.
The reverse breakdown current between the collector and the emitter IEOICEO refers to the reverse between the collector and the emitter when the base of the transistor is open. Leakage current is also called penetration current. The smaller the current value, the better the performance of the transistor.
Switch function
Control high power
Current power transistors can control hundreds of kilowatts of power, using power transistors as switches There are many advantages, mainly;
(1)Easy to turn off, less auxiliary components required,
(2) Fast switching, able to work at a very high frequency ,
(3) The available device withstand voltage ranges from 100V to 700V, everything.
A few years ago, the switching capacity of transistors was less than 10kW. At present, it has been able to control power up to hundreds of kilowatts. This is mainly due to the joint efforts of physicists, technicians and circuit designers to improve the performance of power transistors. Such as
(1) the increase of the effective chip area of the switching transistor,
(2) the simplification of technology,
(3) the combination of transistors-up to Linton,
(4) Advances in base drive technology for high-power switches. ,
Transistor power switch that works directly on rectified 380V mains
Transistor composite (Darlington) and parallel are both effective to increase transistor switches Ability method.
In such high-power circuits, the main problem is wiring. The very high switching speed can produce a very high interference voltage on a short connection line.
High performance created by simple and optimized base drive
Today’s base drive circuit not only drives power transistors, but also protects power transistors, so called It is "non-centralized protection" (contrast with centralized protection). The functions of the integrated drive circuit include:
(1) turn on and off the power switch;
(2) monitor the auxiliary power supply voltage;
(3) limit Maximum and minimum pulse width;
(4) Thermal protection;
(5) Monitor the saturation voltage drop of the switch.
Historical events
Earlier in 2010, Samsung announced that it had completed the development of a 30nm process 2Gb density DDR3 memory chip, and recently (July) they announced this Chip products have entered the mass production stage.
According to Intel engineers, the first CPU with 22nm process is expected to appear in 2011. In February 2009, Intel released a new generation of Westmere core processors using 32nm process, which is the second generation of Nehalem architecture processors. And in 2010, the brand-new SandyBridge core will realize an 8-core design with the help of 32nm process technology.
In November 2007, Intel released a total of 16 Penryn processors, mainly for servers and high-end PCs. These products use a more advanced 45-nanometer production process, the most complex of which has 820 million transistors. Intel’s previous generation products mainly used 65-nanometer production processes, and the most complex processor had 582 million transistors.
IBM will introduce the details of the new transistor design at the San Francisco International Electronic Equipment Conference in December, and will put it into production from 2005 to 2006. Its 210GHz transistor was launched in June 2001, and related chips It will be listed in late 2003 or early 2004.
Experts believe that the bottom line of the lowest price for each transistor appeared in 2003-2005. From an economic point of view, there is no need to make transistors smaller.
By 2005, the number of transistors in the chip will be as high as several billion, and the frequency will be as high as several gigahertz.
It is expected that products with the new TeraHertz transistor architecture will be launched in 2005.
By 2005, when 200 million transistors are integrated on the chip, it will be as hot as a "nuclear reactor". When 2010, the temperature of the chip will reach the temperature level of the high-temperature gas nozzle when the rocket is launched, and by 2015 The chip will be as hot as the surface of the sun.
It is estimated that by 2004, Intel will be able to launch new wafers with a diameter of 300 mm (approximately 12 inches) (wafer size generally doubles in ten years) capable of engraving 5 A chip with billions of transistors.
For example, the 90nm technology put into use in 2004, where the half-pitch is 90nm, and the physical gate length of the transistor is 37nm
In 2004, the industry has introduced ultra-thin SOI wafers. A high-speed CMOS circuit with 0.1μm and 100 million transistors.
The 90nm process used in 2003 has undergone some changes. In addition to the shortening of the line length and gate length, strained silicon (Strainedsi) was introduced into the transistor for the first time to solve the problem of the internal current path of the transistor.
According to statistics, the number of transistors per chip in 2003 increased by 1 billion times compared with 1963.
Barton: In the second half of 2002, AMD will release a Barton core processor using SOI (silicon connected) transistor structure.
At the Microprocessor Forum held in Silicon Valley on September 15, 2002, the world’s chip industry leader, Intel Corporation of the United States, stated that the company will launch an integrated 1 billion transistors in 2007 and run at speeds up to The 6GHz computer chip brought the world's chips into the era of 1 billion transistors, and at the same time proved Moore's Law, the evergreen tree of invention theory.
In May 2002, IBM developed carbon nano transistors that far exceeded the current most advanced silicon transistors, and the process of practical use accelerated again.
In the period from the end of 2001 to the beginning of 2002, Intel's product line will all be transferred to 0.13 micron packaging process, the transistor manufacturing technology used is 70 nanometers.
On September 25, 2001, the Semiconductor Manufacturing International Corporation with an investment of US$1.48 billionManufacturing (Shanghai) Co., Ltd. held the "SMIC First Core" production ceremony in Shanghai Zhangjiang High-tech Park to celebrate the first 8-inch line width below 0.25 microns (refers to the distance between the transistors on the chip, the more The shorter is, the more transistors can be arranged on the same chip, the higher the technical level.) On-line production of chips.
In 2001, Bell Laboratories invented the world's first molecular-level transistor, which became another scientific milestone after the transistor invented in 1947, marking the arrival of a new era of communications and technology.
On July 18, 2001, the Qingdao Transistor Experiment Institute was the first to restructure the Kaidaocheng Scientific Research Institute: 130 employees invested 1 million yuan to buy it out. At that time, the experiment was operated under the state-owned system. For 35 years.
In June 2001, IBM announced that the operating frequency of a single silicon germanium transistor reached 210GHz and the operating current was 1mA, which was 80% faster than the previous generation silicon germanium transistor and reduced power consumption by 50%.
In 2001, Avouris and others used this method to successfully manufacture the world's first row of carbon nanotube transistors 1451.
In April 2001, IBM announced the world's first carbon nanomaterial transistor array, thus making the ideal of a "molecular computer" a reality.
In 2000, Intel launched the "Pentium 4" processor, which runs at a speed of up to 1.5GHz, has a number of integrated transistors of up to 42 million, and has up to 1.5 billion operations per second.
In November 2000, the Pentium 4 processor containing 42 million transistors was born. Its outstanding innovation enabled the processor technology to enter the seventh generation.
In December 2000, Intel took the lead in the industry to develop a single transistor with a gate length of 30nm; in June 2001, Intel increased this record to 20nm; on November 26 of the same year, Intel It is announced that a new transistor with a gate length of only 15nm has been developed, and the actual operating frequency of a single transistor has reached 2.63THz.
By 2000, the productivity of each design engineer for a new design was 2683 transistors/week, while the productivity of designing with IP was about 30,000 transistors/week. The efficiency improvement was very obvious. It can be said IP reuse is an important productivity factor.
At the same time, millimeter-wave power transistors may be transferred to small-batch trial production around 2000.
It is estimated that around 2000, there will be 1GDRAM and monolithic systems that can contain 50 billion transistors in the world.
At the beginning of 2000, Bell Labs in the United States developed a 50nm-oriented transistor. The transistor is built on the surface of the chip, the current flows vertically, and there is a gate on each of the two opposite sides of the transistor, thereby increasing the calculation speed.
For example, more than half of the US$2.88 billion in electromechanical products imported by China from Malaysia in 2000 were picture tubes, transistors and integrated circuits.
At the beginning of 1999, all high-altitude stations across the country began to use transistor answering devices.
In 1998, Feizon Avuris of the Thomas Watson Research Center of International Business Machines Corporation and Seth Decker of the Delft University of Technology in the Netherlands confirmed that a single carbon nanotube has the function of a transistor .
Since the application of carbon nanotubes in the production of field-effect transistors at room temperature in 1998, the research on the production of nano-scale molecular devices from carbon nanotubes has made considerable progress.
According to a report in the Science and Technology Daily on February 26, 1998, Sandia National Laboratory in the United States produced a quantum transistor sample tube based on the basic principles of quantum physics, which solved the mass production process. problem.
In March 1998, Intel made an integrated circuit chip containing 70.2 billion transistors, which shows that integration, an important indicator of microelectronics technology, has increased by 70 million times in less than 40 years.
In 1997, a Pentium processor with 7.5 million transistors was introduced.
In 1997, Intel introduced the Pentium processor with 7.5 million transistors. This new product integrates IntelMMX media enhancement technology, specifically designed for efficient processing of video, audio and graphics data.
In 1997, the productivity of each design engineer for a new design was 1,100 transistors/week, and the productivity of designing with IP modules was 2,100 transistors/week.
We trial-produced a transistor amplifier with higher input impedance, and tried it on the master station on July 29, 1997. As a result, the channel to Zhoubang station was activated, and the communication was not interrupted for several days.
Another breakthrough in microprocessor technology is the innovation of chip manufacturing technology. On September 22, 1997, IBM announced a new process of using copper instead of aluminum to manufacture transistors, making electronic circuits smaller and faster. Faster and more efficient.
In September 1997, IBM announced that it had successfully developed a new production process for producing transistors by replacing aluminum with copper.
Since 1997, through the joint efforts of various manufacturers, users and other relevant departments, most of the provinces and bureaus in the country have already used transistor answering devices.
At the end of 1995, the transistor construction plan was opened. In June 1996, the first batch of production was tested and was very successful.
In 1995, the factory installed two single-bin transistor high-voltage electrostatic precipitators, which were used on the two ball mills of the finished product.
On November 9, 1995, one of the transistor excitation devices was first modified.
For example, in 1995, Sony had mastered the core expertise of transistors and produced the first generation of transistor radios, which were small in size and priced at only US$29.95 each. They were inexpensive and high-quality, and quickly occupied the world market.
At the beginning of 1994, the American LSI company successfully developed a logic chip with an integrated level of 9 million transistors, 0.5μm3V
Japan's Matsushita company was the first to use SMT to produce 10nm quality silicon quantum wires. In 1994, At the International Nano Engineering Conference held in Switzerland, the transistor unit circuit made with STM probes was demonstrated for the first time.
Magnetic Transistor
Magnetic Transistor is made of germanium material or silicon material. The figure is a structural diagram of a magneto-transistor. It is to make N+-i-N+ structure on high-resistance semiconductor material i, and destroy a layer of crystal lattice by sandblasting on one side of the emitter area to form a high carrier recombination area r. The element adopts a plate structure, and the emitting area and the collecting area are arranged on its upper and lower surfaces.
Distinguish and calculation
Distinguish the type of base and tube
Select R*100 (or R*1K in ohm file) ) File, first connect one pin with the red test lead, connect the black test lead to the other pin, two resistance values can be measured, and then connect the other pin with the red test lead, repeat the above steps, and get another set of resistance values , Measured 3 times in this way, there is a group of two resistance values are very small, corresponding to the measured value of the red test lead is connected to the base, and the tube is PNP type; on the contrary, if you use a black test lead to connect a pin , Repeat the above method, if the measured two resistance values are both small, the corresponding black test lead is the base, and the tube is of NPN type.
Distinguish the collector
Because β is large when the emitter and collector of the transistor are connected correctly (the needle swings greatly), β is too small when reverse connection many. Therefore, first assume a collector, which is connected with an ohm file (for NPN tubes, the emitter is connected to the black test lead, and the collector is connected to the red test lead). When measuring, pinch the base and hypothetical collector with your hands. The two poles cannot be in contact. If the pointer swings greatly, and the pointer swings small after the two poles are swapped, it means that the hypothesis is correct, so as to determine the collector and emitter.
Estimation of the current amplification factor β
Select the R*100 (or R*1K) file of the ohm file. For the NPN tube, the red meter pen is connected The emitter and the black test lead are connected to the collector. When measuring, just compare the size of the small pointer swing when you hold the base and the collector with your hand (the two electrodes cannot be touched) and release the hand. The larger the swing, the higher the β value. .
Detection and replacement
The transistors in the circuit mainly include crystal diodes, transistors, thyristors and field effect transistors, etc. The most commonly used ones are transistors and diodes. How to correctly Judging the quality of the secondary and triode is one of the keys to learning maintenance.
1 Crystal diode: First of all, we need to know whether the diode is a silicon tube or a germanium tube. The forward voltage drop of a germanium tube is generally between 0.1 volts and 0.3 volts, while a silicon tube is generally 0.6 volts. Between 0.7 volts. The measurement method is: use two multimeters to measure, when one multimeter is measuring its forward resistance, another multimeter is used to measure its tube pressure drop. Finally, it can be judged whether it is a germanium tube or a silicon tube according to the value of the tube pressure drop. The silicon tube can be measured with the R×1K block of a multimeter, and the germanium tube can be measured with the R×100 block. Generally speaking, the greater the difference between the forward and reverse resistance of the measured diode, the better. Generally, if the forward resistance is hundreds to thousands of ohms and the reverse resistance is more than tens of kiloohms, it can be preliminarily concluded that the diode is good. At the same time, the positive and negative poles of the diode can be determined. When the measured resistance value is hundreds of ohms or thousands of ohms, it is the forward resistance of the diode. At this time, the negative electrode is connected to the negative electrode and the positive electrode is connected to the positive electrode. In addition, if the forward and reverse resistance is infinite, it means that its internal disconnection; the forward and reverse resistance is the same, such a diode is also a problem; the forward and reverse resistance are all zero, indicating that it has been short-circuited.
2 Transistor: The transistor is mainly used for amplification, so how to judge the amplification ability of the transistor? The method is: adjust the multimeter to the R×100 block or R×1K block. When measuring the NPN tube, connect the positive test lead to the emitter and the negative test lead to the collector. The measured resistance should generally be several thousand ohms or more; Then connect a 100kohm resistor in series between the base and the collector. At this time, the resistance measured by the multimeter should be significantly reduced. The greater the change, the stronger the amplification capability of the triode. If the change is small or fundamental If there is no change, it means that the triode has no amplification ability or is very weak.
How to determine the electrode
The germanium tube used for measurement uses R*100 file, and the silicon tube uses R*1k file. Foot measurement. See if you can find two small resistors. If you can't move the red test lead to the other pin and continue to measure, take care of the two small resistors. If you can't find two small resistors by fixing the red wire, you can fix the black test lead and continue searching.
When two small resistors are found, the fixed test lead is used as the base electrode. If the fixed test pen is a black pen, the transistor is of NPN type, if the fixed pen is a red pen, the tube is PNP.
A method of judging ce pole resistance
Use a multimeter to measure the resistance of the two poles except the base pole, exchange the test leads to test twice, if it is a germanium tube, the measured resistance is the smaller one If it is PNP type, the black test lead is connected to the emitter, the red test lead is connected to the collector, if it is NPN type, the black test lead is connected to the collector, and the red test lead is connected to the emitter; if it is For silicon tube, the larger the resistance is measured. If it is PNP type, the black test lead is connected to the emitter and the red test lead is connected to the collector. If it is NPN type, the black test lead is connected to the collector. , The red test lead is connected to the emitter.
BPN junction forward resistance method
Measure the forward resistance of two PN junctions separately, the larger one is the emitter and the smaller one is the collector.
C magnification factor method
Use the two test leads of the multimeter to contact the two feet except the base. If it is PNP, touch the base and the red pen with your fingers. Look at the situation of the pointer swing, and then exchange the test pen to measure once, whichever is the largest swing of the pointer. At this time, connect the red test pen as the collector; if it is NPN, touch the base electrode and the red pen with your finger. The second pole depends on the situation of the pointer swing, and then exchange the test pen to test once, whichever is the largest swing of the pointer. At this time, connect the black test pen as the collector.
Note: The difference between an analog meter and a digital meter is that the red test lead of the analog meter is connected to the negative pole of the power supply, while the digital meter is the opposite.
Detection method
1. Detection of ordinary Darlington tube
There are two or more common Darlington tubes inside. Only the collectors of the transistors are connected together to form a composite, and the base b and the emitter e include multiple emitter junctions. The R×1kΩ or R×10kΩ gear of a multimeter can be used to measure.
Measure the forward and reverse resistance values between the electrodes of the Darlington tube. Normally, the forward resistance between collector c and base b (when measuring NPN tube, the black test lead is connected to base b; when measuring PNP tube, the black test lead is connected to collector c) and the collector junction of ordinary silicon transistors The forward resistance value is similar, ranging from 3 to 10kΩ, and the reverse resistance value is infinite. And the forward resistance value between emitter e and base b (when measuring NPN tube, the black meter pen is connected to base b; when measuring PNP tube, the black meter pen is connected to emitter e) is between collector c and base b The forward resistance value is 2 to 3 times, and the reverse resistance value is infinite. The forward and reverse resistance values between the collector c and the emitter e should be close to infinity. If the forward and reverse resistance values between the c and e poles of the Darlington tube or the forward and reverse resistance values between the b, e, b and c poles are close to 0, it means that the tube has broken down. damage. If the measured value of the forward and reverse resistance between the b, e poles b, and c poles of the Darlington tube is infinite, it means that the tube has been opened and damaged.
2. Detection of high-power Darlington tube
The high-power Darlington has added a continuous flow based on the ordinary Darlington tube. For the protection circuit composed of diodes and bleeder resistors, attention should be paid to the influence of these components on the measurement data during measurement.
Use a multimeter to measure the forward and reverse resistance values of the Darlington collector junction (between collector c and base b) in the R×1kΩ or R×10kΩ gear. Normally, the forward resistance value (when the base of the NPN tube is connected to the black test lead) should be small, 1-10kΩ, and the reverse resistance value should be close to infinity. If the measured forward and reverse resistance values of the collector junction are both small or infinite, it means that the tube has been broken down and short-circuited or open-circuited and damaged.
Use a multimeter to measure the forward and reverse resistance values between the emitter e and base b of the Darlington tube. The normal values are from several hundred ohms to several thousand ohms (specific data It varies according to the resistance of the two resistors between the b and e poles. For example: BU932R, MJ10025 and other high-power Darlington tubes. The forward and reverse resistance values between the b and e poles are both about 600Ω ), if the measured resistance value is 0 or infinity, it means that the tube under test has been damaged.
Using a multimeter R×lkΩ or R×10kΩ, measure the forward and reverse resistance values between the emitter e and collector c of the Darlington tube. Normally, the forward resistance value (When measuring NPN tube, the black test lead is connected to emitter e, and the red test lead is connected to collector c; when measuring PNP tube, the black test lead is connected to collector c, and the red test lead is connected to emitter e) should be 5～15kΩ (BU932R is 7kΩ). The direction resistance value should be infinite, otherwise the c and e poles (or diode) of the tube will break down or be damaged by the open circuit.
The smallest transistor
Beijing time on May 26, 2010, according to the physicist organization network report, American and Australian scientists have successfully manufactured the world’s smallest transistor-consisting of 7 A "quantum dot" formed by atoms on the surface of single crystal silicon marks an important step for us to a new era of computing power. Quantum dots are nano-sized light-emitting crystals, sometimes called "artificial atoms". Although this quantum dot is very small, only four billionths of a meter in length, it is a fully functional electronic device and the world's first electronic device deliberately made with atoms. Not only can it be used to regulate and control the current of devices such as commercial transistors, but it also marks an important step towards a new era of atomic scale miniaturization and ultra-high-speed and ultra-powerful computers.
A joint team composed of researchers from the Centre for Quantum Computer Technology (CQCT) of the University of New South Wales in Australia and the University of Wisconsin-Madison in the latest issue of the "Nature Nanotechnology" (NatureNanotechnology) magazine detailed Describes this discovery. Professor Michelle Simmons, director of the Quantum Computer Technology Center who participated in this research, said: "The importance of this achievement is that we are not making atoms move or observing atoms under a microscope, but manipulating individual atoms. Put it on the surface with atomic precision to make electronic devices that can work."
"The Australian research team has been able to use crystalline silicon to make electronic devices. We replaced 7 with phosphorous atoms on the crystalline silicon. A silicon atom with amazing accuracy. This is a major technological achievement and a key step to show the feasibility of making the “ultimate computer” (quantum computer made from silicon atoms)." Placing the atom on the surface of an object The technology-scanning tunneling microscope-has been around for twenty years. Before that, no one could use this technology to make atomically accurate electronic devices, and then make them process the electronic input from the microscopic world.
Professor Simmons said: “How small can electronic devices be? We are verifying its limits. Australia’s first computer was launched in 1949. It occupies the entire room and you can only use your hands. Hold the parts. Today, you can put the computer on the palm of your hand. The diameter of many parts is only one thousandth of the diameter of a hair."
"Now we have shown the world’s first An electronic device that is systematically manufactured with silicon material under the atomic scale. This is not only of special significance for computer users, but also extremely important for all Australians. For the past 50 years, the miniaturization of electronic devices has been driving the productivity of the global economy The key factor for rapid growth. Our research shows that this process can continue."
The main goal of the US-Australia joint research team is to use silicon atoms to make quantum computers. Australians have unique manpower in this field. Resources, and at the same time in a leading position in the world. This new electronic device shows that the technology to realize the manufacture and measurement of equipment under the atomic scale has begun to come.
Currently, the length of the commercial transistor gate (transistorgate, a device that allows the transistor to act as an amplifier or switch for current) is about 40 nanometers (1 nanometer is equivalent to one billionth of a meter). Quantum computer technology The center’s research team is developing a device with a length of only 0.4 nanometers.
Professor Simmons pointed out that 20 years ago, Don Eigler and Erhard Schweizer used xenon atoms at IBM’s Almaden Research Center to create The IBM logo, which was also the smallest logo in the world at that time. The two used a scanning tunneling microscope to place 35 xenon atoms on the surface of nickel and spelled out the three letters "IBM".
The research paper of Aigle and Schweitzer was published in the journal Nature. They wrote: "The basic principle of equipment miniaturization is obvious." The two also warned many times in the paper, and concluded at the end: "The prospect of atomic scale logic circuits and other equipment is a little far away from us." Professor Simmons said: "What seemed remote at the time has now become Reality. We can use this microscope not only to observe or manipulate atoms, but also to use 7 atoms to make atomic-precision equipment, so that it can work in a real environment."
Three-dimensional transistor
Intel announced on May 4, 2011 that it has developed transistors with a three-dimensional structure that can be put into mass production. Chips using new transistors are expected to greatly improve their performance while reducing energy consumption.
Intel also demonstrated the 22-nanometer microprocessor code-named "Ivy Bridge" on the same day, and plans to complete preparations for mass production of the microprocessor by the end of this year. Intel said it will be the first mass-produced chip to use a new three-dimensional transistor. Compared with two-dimensional transistors that are currently widely used in computers and other products, three-dimensional transistors have technological breakthroughs. Intel said that its researchers invented a three-dimensional transistor with a "tri-gate" structure in 2002. After years of research and development, this new type of transistor has finally entered the stage of mass production. The company explained that similar to skyscrapers that optimize the use of limited space in cities by expanding into the air, three-dimensional transistors have a more vertical structure than two-dimensional transistors, so that the transistors in the chip can be more tightly packaged. Data provided by Intel shows that, compared with the two-dimensional transistors used in the company's 32-nanometer chip, the performance of three-dimensional transistors at low voltage can be increased by 37%, and the energy consumption for completing the same work can be reduced by half. Intel experts said that these advantages mean that the new transistors are very suitable for small handheld devices, which are expected to further improve the intelligence of existing devices and make it possible to design and develop other new devices.
Tri-gate transistor and traditional transistor principle introduction video, introduced by Mark T.bohr, senior manager of Intel Process Architecture and Integration Department, and borrowed from Youku video platform to watch.
Substitution principle
Whether it is professional radio maintenance personnel. I am still an amateur radio enthusiast, and I will encounter the problem of transistor replacement at work. If the principle of transistor substitution is mastered, the maintenance work can often be doubled and the maintenance efficiency can be improved. Transistor replacement principles can be summarized as three: the same type, similar characteristics, and similar appearance.
One, the same type
1. The materials are the same. That is, the germanium tube replaces the germanium tube, and the silicon tube replaces the silicon tube.
2. The polarity is the same. That is, the npn-type tube replaces the npn-type tube, and the pnp-type tube replaces the pnp-type tube.
Second, similar characteristics
The characteristics of the transistors used for replacement should be similar to those of the original transistors, and their main parameter values and characteristic curves should be similar. There are nearly 20 main parameters of the transistor, and all these parameters are required to be similar, which is not only difficult, but also unnecessary. Generally speaking, as long as the following main parameters are similar, the replacement requirements can be met.
1. The maximum DC dissipation power of the collector plate (pcm)
Generally, it is required to replace it with a transistor with a pcm equal to or larger than the original tube. However, after calculation or testing, if the actual DC dissipation power of the original transistor in the complete circuit is much smaller than its pcm, it can be replaced with a transistor with a smaller pcm.
2. The maximum allowable DC current of the collector (icm)
Generally, it is required to replace it with a transistor whose icm is equal to or larger than the original tube.
3. Breakdown voltage
The transistor used for replacement must be able to safely withstand the highest working voltage in the whole machine;
Source: Transmission and Distribution Equipment Network
4. Frequency characteristics
Transistor frequency characteristics parameters, commonly used are the following two:
(1) Characteristic frequency ft: It refers to the common emitter of transistors when the test frequency is high enough The frequency of the current amplification factor.
(2) Cutoff frequency fb:
When replacing the transistor, the main considerations are ft and fb. It is generally required that the ft and fb of the transistor used for replacement should not be less than the corresponding ft and fb of the original transistor.
5. Other parameters
In addition to the above main parameters, for some special transistors, the following parameters should be considered when replacing:
(1) For low-noise transistors, the following parameters should be used when replacing A transistor with a smaller or equal noise figure.
(2) For transistors with automatic gain control performance, transistors with the same automatic gain control characteristics should be used when replacing them.
(3) For the switching tube, its switching parameters should also be considered when replacing it.
Three, similar appearance
Low power transistors are generally similar in appearance, as long as the lead wires of each electrode are clearly marked and the lead wires are arranged in the same order as the tubes to be replaced, they can be replaced. The appearance of high-power transistors is quite different. When replacing, you should choose transistors with similar appearance and the same installation size to install and maintain normal heat dissipation conditions.