110-413: The field-effect transistor ( FET ) is a type of transistor that uses an electric field to control the current through a semiconductor . It comes in two types: junction FET (JFET) and metal-oxide-semiconductor FET (MOSFET). FETs have three terminals: source , gate , and drain . FETs control the current by the application of a voltage to the gate, which in turn alters the conductivity between
220-501: A field-effect transistor , or may have two kinds of charge carriers in bipolar junction transistor devices. Compared with the vacuum tube , transistors are generally smaller and require less power to operate. Certain vacuum tubes have advantages over transistors at very high operating frequencies or high operating voltages, such as Traveling-wave tubes and Gyrotrons . Many types of transistors are made to standardized specifications by multiple manufacturers. The thermionic triode ,
330-532: A p-n-p transistor symbol, the arrow " P oints i N P roudly". However, this does not apply to MOSFET-based transistor symbols as the arrow is typically reversed (i.e. the arrow for the n-p-n points inside). The field-effect transistor , sometimes called a unipolar transistor , uses either electrons (in n-channel FET ) or holes (in p-channel FET ) for conduction. The four terminals of the FET are named source , gate , drain , and body ( substrate ). On most FETs,
440-521: A tokamak system for the realization of controlled thermonuclear fusion on the basis of toroidal magnetic thermonuclear reactor and soon after the first such devices were built by the INF. Results from the T-3 Soviet magnetic confinement device in 1968, when the plasma parameters unique for that time were obtained, showed temperatures in their machine to be over an order of magnitude higher than what
550-476: A vacuum tube invented in 1907, enabled amplified radio technology and long-distance telephony . The triode, however, was a fragile device that consumed a substantial amount of power. In 1909, physicist William Eccles discovered the crystal diode oscillator . Physicist Julius Edgar Lilienfeld filed a patent for a field-effect transistor (FET) in Canada in 1925, intended as a solid-state replacement for
660-488: A BJT. Because the FETs are controlled by gate charge, once the gate is closed or open, there is no additional power draw, as there would be with a bipolar junction transistor or with non-latching relays in some states. This allows extremely low-power switching, which in turn allows greater miniaturization of circuits because heat dissipation needs are reduced compared to other types of switches. A field-effect transistor has
770-578: A device had been built. In 1934, inventor Oskar Heil patented a similar device in Europe. From November 17 to December 23, 1947, John Bardeen and Walter Brattain at AT&T 's Bell Labs in Murray Hill, New Jersey , performed experiments and observed that when two gold point contacts were applied to a crystal of germanium , a signal was produced with the output power greater than the input. Solid State Physics Group leader William Shockley saw
880-600: A few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved. Modern transistor audio amplifiers of up to a few hundred watts are common and relatively inexpensive. Before transistors were developed, vacuum (electron) tubes (or in the UK "thermionic valves" or just "valves") were the main active components in electronic equipment. The key advantages that have allowed transistors to replace vacuum tubes in most applications are Transistors may have
990-425: A field-effect transistor (FET) by trying to modulate the conductivity of a semiconductor, but was unsuccessful, mainly due to problems with the surface states , the dangling bond , and the germanium and copper compound materials. Trying to understand the mysterious reasons behind this failure led them instead to invent the bipolar point-contact and junction transistors . In 1948, the point-contact transistor
1100-451: A high degree of isolation between control and flow. Because base current noise will increase with shaping time, a FET typically produces less noise than a bipolar junction transistor (BJT), and is found in noise-sensitive electronics such as tuners and low-noise amplifiers for VHF and satellite receivers. It exhibits no offset voltage at zero drain current and makes an excellent signal chopper. It typically has better thermal stability than
1210-451: A high quality Si/ SiO 2 stack in 1960. Following this research, Mohamed Atalla and Dawon Kahng proposed a silicon MOS transistor in 1959 and successfully demonstrated a working MOS device with their Bell Labs team in 1960. Their team included E. E. LaBate and E. I. Povilonis who fabricated the device; M. O. Thurston, L. A. D’Asaro, and J. R. Ligenza who developed the diffusion processes, and H. K. Gummel and R. Lindner who characterized
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#17327569140651320-433: A layer of silicon dioxide over the silicon wafer, for which they observed surface passivation effects. By 1957 Frosch and Derrick, using masking and predeposition, were able to manufacture silicon dioxide transistors and showed that silicon dioxide insulated, protected silicon wafers and prevented dopants from diffusing into the wafer. J.R. Ligenza and W.G. Spitzer studied the mechanism of thermally grown oxides and fabricated
1430-413: A negative gate-to-source voltage causes a depletion region to expand in width and encroach on the channel from the sides, narrowing the channel. If the active region expands to completely close the channel, the resistance of the channel from source to drain becomes large, and the FET is effectively turned off like a switch (see right figure, when there is very small current). This is called "pinch-off", and
1540-625: A noble Rurikid Shuysky family. They eventually had two children, Irina (1921–2009, chemist) and Evgeny (1926–2008, experimental physicist and famous mountain climber, leader of the Soviet Everest expedition in 1982 ). On 1 May 1923, Tamm began teaching physics at the Second Moscow State University . The same year, he finished his first scientific paper, Electrodynamics of the Anisotropic Medium in
1650-424: A p-channel "enhancement-mode" device, a conductive region does not exist and negative voltage must be used to generate a conduction channel. For either enhancement- or depletion-mode devices, at drain-to-source voltages much less than gate-to-source voltages, changing the gate voltage will alter the channel resistance, and drain current will be proportional to drain voltage (referenced to source voltage). In this mode
1760-433: A p-type semiconductor. The drain and source may be doped of opposite type to the channel, in the case of enhancement mode FETs, or doped of similar type to the channel as in depletion mode FETs. Field-effect transistors are also distinguished by the method of insulation between channel and gate. Types of FETs include: Field-effect transistors have high gate-to-drain current resistance, of the order of 100 MΩ or more, providing
1870-412: A particular type, varies depending on the collector current. In the example of a light-switch circuit, as shown, the resistor is chosen to provide enough base current to ensure the transistor is saturated. The base resistor value is calculated from the supply voltage, transistor C-E junction voltage drop, collector current, and amplification factor beta. The common-emitter amplifier is designed so that
1980-485: A patent for FET in which germanium monoxide was used as a gate dielectric, but he didn't pursue the idea. In his other patent filed the same year he described a double gate FET. In March 1957, in his laboratory notebook, Ernesto Labate, a research scientist at Bell Labs , conceived of a device similar to the later proposed MOSFET, although Labate's device didn't explicitly use silicon dioxide as an insulator. In 1955, Carl Frosch and Lincoln Derrick accidentally grew
2090-402: A properly designed circuit. FETs often have a very low "on" resistance and have a high "off" resistance. However, the intermediate resistances are significant, and so FETs can dissipate large amounts of power while switching. Thus, efficiency can put a premium on switching quickly, but this can cause transients that can excite stray inductances and generate significant voltages that can couple to
2200-484: A relatively low gain–bandwidth product compared to a bipolar junction transistor. MOSFETs are very susceptible to overload voltages, thus requiring special handling during installation. The fragile insulating layer of the MOSFET between the gate and the channel makes it vulnerable to electrostatic discharge or changes to threshold voltage during handling. This is not usually a problem after the device has been installed in
2310-438: A research paper and patented their technique summarizing their work. The technique they developed is known as oxide diffusion masking, which would later be used in the fabrication of MOSFET devices. At Bell Labs, the importance of Frosch's technique was immediately realized. Results of their work circulated around Bell Labs in the form of BTL memos before being published in 1957. At Shockley Semiconductor , Shockley had circulated
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#17327569140652420-467: A silicon MOS transistor in 1959 and successfully demonstrated a working MOS device with their Bell Labs team in 1960. Their team included E. E. LaBate and E. I. Povilonis who fabricated the device; M. O. Thurston, L. A. D’Asaro, and J. R. Ligenza who developed the diffusion processes, and H. K. Gummel and R. Lindner who characterized the device. With its high scalability , much lower power consumption, and higher density than bipolar junction transistors,
2530-605: A small change in voltage ( V in ) changes the small current through the base of the transistor whose current amplification combined with the properties of the circuit means that small swings in V in produce large changes in V out . Various configurations of single transistor amplifiers are possible, with some providing current gain, some voltage gain, and some both. From mobile phones to televisions , vast numbers of products include amplifiers for sound reproduction , radio transmission , and signal processing . The first discrete-transistor audio amplifiers barely supplied
2640-669: A theory of meson forces . In 1945 he developed an approximation method for many-body physics. As Sidney Dancoff developed it independently in 1950, it is now called the Tamm-Dancoff approximation. He was the Nobel Laureate in Physics for the year 1958 together with Pavel Cherenkov and Ilya Frank for the discovery and the interpretation of the Cherenkov-Vavilov effect . In late 1940s to early 1950s Tamm
2750-440: A type of 3D non-planar multi-gate MOSFET, originated from the research of Digh Hisamoto and his team at Hitachi Central Research Laboratory in 1989. Because transistors are the key active components in practically all modern electronics , many people consider them one of the 20th century's greatest inventions. The invention of the first transistor at Bell Labs was named an IEEE Milestone in 2009. Other Milestones include
2860-441: A variety of materials such as silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), and indium gallium arsenide (InGaAs). In June 2011, IBM announced that it had successfully used graphene -based FETs in an integrated circuit . These transistors are capable of about 2.23 GHz cutoff frequency, much higher than standard silicon FETs. The channel of a FET is doped to produce either an n-type semiconductor or
2970-416: A weaker input signal, acting as an amplifier . It can also be used as an electrically controlled switch , where the amount of current is determined by other circuit elements. There are two types of transistors, with slight differences in how they are used: The top image in this section represents a typical bipolar transistor in a circuit. A charge flows between emitter and collector terminals depending on
3080-461: A working bipolar NPN junction amplifying germanium transistor. Bell announced the discovery of this new "sandwich" transistor in a press release on July 4, 1951. The first high-frequency transistor was the surface-barrier germanium transistor developed by Philco in 1953, capable of operating at frequencies up to 60 MHz . They were made by etching depressions into an n-type germanium base from both sides with jets of indium(III) sulfate until it
3190-418: Is a semiconductor device used to amplify or switch electrical signals and power . It is one of the basic building blocks of modern electronics . It is composed of semiconductor material , usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because
3300-411: Is connected to the highest or lowest voltage within the circuit, depending on the type of the FET. The body terminal and the source terminal are sometimes connected together since the source is often connected to the highest or lowest voltage within the circuit, although there are several uses of FETs which do not have such a configuration, such as transmission gates and cascode circuits. Unlike BJTs,
3410-430: Is effective as a buffer in common-drain (source follower) configuration. IGBTs are used in switching internal combustion engine ignition coils, where fast switching and voltage blocking capabilities are important. Source-gated transistors are more robust to manufacturing and environmental issues in large-area electronics such as display screens, but are slower in operation than FETs. Transistor A transistor
Field-effect transistor - Misplaced Pages Continue
3520-434: Is increased further, the pinch-off point of the channel begins to move away from the drain towards the source. The FET is said to be in saturation mode ; although some authors refer to it as active mode , for a better analogy with bipolar transistor operating regions. The saturation mode, or the region between ohmic and saturation, is used when amplification is needed. The in-between region is sometimes considered to be part of
3630-417: Is necessary to create one. The positive voltage attracts free-floating electrons within the body towards the gate, forming a conductive channel. But first, enough electrons must be attracted near the gate to counter the dopant ions added to the body of the FET; this forms a region with no mobile carriers called a depletion region , and the voltage at which this occurs is referred to as the threshold voltage of
3740-481: Is not observed in modern devices, for example, at the 65 nm technology node. For low noise at narrow bandwidth , the higher input resistance of the FET is advantageous. FETs are divided into two families: junction FET ( JFET ) and insulated gate FET (IGFET). The IGFET is more commonly known as a metal–oxide–semiconductor FET ( MOSFET ), reflecting its original construction from layers of metal (the gate), oxide (the insulation), and semiconductor. Unlike IGFETs,
3850-421: Is often easier and cheaper to use a standard microcontroller and write a computer program to carry out a control function than to design an equivalent mechanical system. A transistor can use a small signal applied between one pair of its terminals to control a much larger signal at another pair of terminals, a property called gain . It can produce a stronger output signal, a voltage or current, proportional to
3960-634: Is the MOSFET (metal–oxide–semiconductor field-effect transistor). The concept of a field-effect transistor (FET) was first patented by the Austro-Hungarian born physicist Julius Edgar Lilienfeld in 1925 and by Oskar Heil in 1934, but they were unable to build a working practical semiconducting device based on the concept. The transistor effect was later observed and explained by John Bardeen and Walter Houser Brattain while working under William Shockley at Bell Labs in 1947, shortly after
4070-423: Is the MOSFET . The CMOS (complementary metal oxide semiconductor) process technology is the basis for modern digital integrated circuits . This process technology uses an arrangement where the (usually "enhancement-mode") p-channel MOSFET and n-channel MOSFET are connected in series such that when one is on, the other is off. In FETs, electrons can flow in either direction through the channel when operated in
4180-797: The University of Edinburgh together with his school-friend Boris Hessen . At the outbreak of World War I in 1914 he joined the army as a volunteer field medic. In 1917 he joined the Revolutionary movement and became an active anti-war campaigner, serving on revolutionary committees after the March Revolution. He returned to the Moscow State University from which he graduated in 1918. Tamm married Nataliya Shuyskaya (1894–1980) in September 1917. Shе belonged to
4290-413: The emitter , collector , and base of BJTs . Most FETs have a fourth terminal called the body , base , bulk , or substrate . This fourth terminal serves to bias the transistor into operation; it is rare to make non-trivial use of the body terminal in circuit designs, but its presence is important when setting up the physical layout of an integrated circuit . The size of the gate, length L in
4400-493: The metal–oxide–semiconductor field-effect transistor (MOSFET), the MOSFET was invented at Bell Labs between 1955 and 1960. Transistors revolutionized the field of electronics and paved the way for smaller and cheaper radios , calculators , computers , and other electronic devices. Most transistors are made from very pure silicon , and some from germanium , but certain other semiconductor materials are sometimes used. A transistor may have only one kind of charge carrier in
4510-471: The point-contact transistor in 1947, which was followed by Shockley's bipolar junction transistor in 1948. The first FET device to be successfully built was the junction field-effect transistor (JFET). A JFET was first patented by Heinrich Welker in 1945. The static induction transistor (SIT), a type of JFET with a short channel, was invented by Japanese engineers Jun-ichi Nishizawa and Y. Watanabe in 1950. Following Shockley's theoretical treatment on
Field-effect transistor - Misplaced Pages Continue
4620-467: The point-contact transistor . Lillian Hoddeson argues that "had Brattain and Bardeen been working with silicon instead of germanium they would have stumbled across a successful field effect transistor". By the end of the first half of the 1950s, following theoretical and experimental work of Bardeen, Brattain, Kingston, Morrison and others, it became more clear that there were two types of surface states. Fast surface states were found to be associated with
4730-399: The surface state barrier that prevented the external electric field from penetrating the material. In 1955, Carl Frosch and Lincoln Derick accidentally grew a layer of silicon dioxide over the silicon wafer, for which they observed surface passivation effects. By 1957 Frosch and Derick, using masking and predeposition, were able to manufacture silicon dioxide field effect transistors;
4840-441: The 17-year patent expired. Shockley initially attempted to build a working FET by trying to modulate the conductivity of a semiconductor , but was unsuccessful, mainly due to problems with the surface states , the dangling bond , and the germanium and copper compound materials. In the course of trying to understand the mysterious reasons behind their failure to build a working FET, it led to Bardeen and Brattain instead inventing
4950-406: The FET operates like a variable resistor and the FET is said to be operating in a linear mode or ohmic mode. If drain-to-source voltage is increased, this creates a significant asymmetrical change in the shape of the channel due to a gradient of voltage potential from source to drain. The shape of the inversion region becomes "pinched-off" near the drain end of the channel. If drain-to-source voltage
5060-477: The FET. Further gate-to-source voltage increase will attract even more electrons towards the gate which are able to create an active channel from source to drain; this process is called inversion . In a p-channel "depletion-mode" device, a positive voltage from gate to body widens the depletion layer by forcing electrons to the gate-insulator/semiconductor interface, leaving exposed a carrier-free region of immobile, positively charged acceptor ions. Conversely, in
5170-628: The JFET gate forms a p–n diode with the channel which lies between the source and drains. Functionally, this makes the n-channel JFET the solid-state equivalent of the vacuum tube triode which, similarly, forms a diode between its grid and cathode . Also, both devices operate in the depletion-mode , they both have a high input impedance, and they both conduct current under the control of an input voltage. Igor Tamm Igor Yevgenyevich Tamm ([И́горь Евге́ньевич Тамм] Error: {{Langx}}: invalid parameter: |a= ( help ) ; 8 July 1895 – 12 April 1971)
5280-407: The JFET in 1952, a working practical JFET was built by George C. Dacey and Ian M. Ross in 1953. However, the JFET still had issues affecting junction transistors in general. Junction transistors were relatively bulky devices that were difficult to manufacture on a mass-production basis, which limited them to a number of specialised applications. The insulated-gate field-effect transistor (IGFET)
5390-412: The MOSFET made it possible to build high-density integrated circuits, allowing the integration of more than 10,000 transistors in a single IC. Bardeen and Brattain's 1948 inversion layer concept forms the basis of CMOS technology today. The CMOS (complementary MOS ) was invented by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. The first report of a floating-gate MOSFET
5500-775: The Regency Division of Industrial Development Engineering Associates, I.D.E.A. and Texas Instruments of Dallas, Texas, the TR-1 was manufactured in Indianapolis, Indiana. It was a near pocket-sized radio with four transistors and one germanium diode. The industrial design was outsourced to the Chicago firm of Painter, Teague and Petertil. It was initially released in one of six colours: black, ivory, mandarin red, cloud grey, mahogany and olive green. Other colours shortly followed. The first production all-transistor car radio
5610-655: The Special Theory of Relativity . In 1928, he spent a few months with Paul Ehrenfest at the University of Leiden and made a life-long friendship with Paul Dirac . From 1934 until his death in 1971 Tamm was the head of the theoretical department at Lebedev Physical Institute in Moscow. In 1932, Tamm published a paper with his proposal of the concept of surface states . This concept is important for metal–oxide–semiconductor field-effect transistor ( MOSFET ) physics. In 1934, Tamm and Semen Altshuller suggested that
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#17327569140655720-468: The basis of CMOS technology today. CMOS (complementary MOS), a semiconductor device fabrication process for MOSFETs, was developed by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. The first report of a floating-gate MOSFET was made by Dawon Kahng and Simon Sze in 1967. The concept of a double-gate thin-film transistor (TFT) was proposed by H. R. Farrah ( Bendix Corporation ) and R. F. Steinberg in 1967. A double-gate MOSFET
5830-431: The basis of modern digital electronics since the late 20th century, paving the way for the digital age . The US Patent and Trademark Office calls it a "groundbreaking invention that transformed life and culture around the world". Its ability to be mass-produced by a highly automated process ( semiconductor device fabrication ), from relatively basic materials, allows astonishingly low per-transistor costs. MOSFETs are
5940-404: The body is connected to the source inside the package, and this will be assumed for the following description. In a FET, the drain-to-source current flows via a conducting channel that connects the source region to the drain region. The conductivity is varied by the electric field that is produced when a voltage is applied between the gate and source terminals, hence the current flowing between
6050-480: The bulk and a semiconductor/oxide interface. Slow surface states were found to be associated with the oxide layer because of adsorption of atoms, molecules and ions by the oxide from the ambient. The latter were found to be much more numerous and to have much longer relaxation times . At the time Philo Farnsworth and others came up with various methods of producing atomically clean semiconductor surfaces. In 1955, Carl Frosch and Lincoln Derrick accidentally covered
6160-456: The channel are free to move out of the channel through the depletion region if attracted to the drain by drain-to-source voltage. The depletion region is free of carriers and has a resistance similar to silicon . Any increase of the drain-to-source voltage will increase the distance from drain to the pinch-off point, increasing the resistance of the depletion region in proportion to the drain-to-source voltage applied. This proportional change causes
6270-642: The channel. FETs can be constructed from various semiconductors, out of which silicon is by far the most common. Most FETs are made by using conventional bulk semiconductor processing techniques , using a single crystal semiconductor wafer as the active region, or channel. Among the more unusual body materials are amorphous silicon , polycrystalline silicon or other amorphous semiconductors in thin-film transistors or organic field-effect transistors (OFETs) that are based on organic semiconductors ; often, OFET gate insulators and electrodes are made of organic materials, as well. Such FETs are manufactured using
6380-437: The collector to the emitter. If the voltage difference between the collector and emitter were zero (or near zero), the collector current would be limited only by the load resistance (light bulb) and the supply voltage. This is called saturation because the current is flowing from collector to emitter freely. When saturated, the switch is said to be on . The use of bipolar transistors for switching applications requires biasing
6490-400: The concept of a field-effect transistor (FET) in 1926, but it was not possible to construct a working device at that time. The first working device was a point-contact transistor invented in 1947 by physicists John Bardeen , Walter Brattain , and William Shockley at Bell Labs who shared the 1956 Nobel Prize in Physics for their achievement. The most widely used type of transistor is
6600-445: The concept of an inversion layer, forms the basis of CMOS and DRAM technology today. In the early years of the semiconductor industry , companies focused on the junction transistor , a relatively bulky device that was difficult to mass-produce , limiting it to several specialized applications. Field-effect transistors (FETs) were theorized as potential alternatives, but researchers could not get them to work properly, largely due to
6710-416: The conductivity of the inversion layer. Further experiments led them to replace electrolyte with a solid oxide layer in the hope of getting better results. Their goal was to penetrate the oxide layer and get to the inversion layer. However, Bardeen suggested they switch from silicon to germanium and in the process their oxide got inadvertently washed off. They stumbled upon a completely different transistor,
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#17327569140656820-449: The controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits . Because transistors are the key active components in practically all modern electronics , many people consider them one of the 20th century's greatest inventions. Physicist Julius Edgar Lilienfeld proposed
6930-559: The current in the base. Because the base and emitter connections behave like a semiconductor diode, a voltage drop develops between them. The amount of this drop, determined by the transistor's material, is referred to as V BE . (Base Emitter Voltage) Transistors are commonly used in digital circuits as electronic switches which can be either in an "on" or "off" state, both for high-power applications such as switched-mode power supplies and for low-power applications such as logic gates . Important parameters for this application include
7040-509: The current is mainly due to a flow of minority carriers. The device consists of an active channel through which charge carriers, electrons or holes , flow from the source to the drain. Source and drain terminal conductors are connected to the semiconductor through ohmic contacts . The conductivity of the channel is a function of the potential applied across the gate and source terminals. The FET's three terminals are: All FETs have source , drain , and gate terminals that correspond roughly to
7150-456: The current switched, the voltage handled, and the switching speed, characterized by the rise and fall times . In a switching circuit, the goal is to simulate, as near as possible, the ideal switch having the properties of an open circuit when off, the short circuit when on, and an instantaneous transition between the two states. Parameters are chosen such that the "off" output is limited to leakage currents too small to affect connected circuitry,
7260-413: The device. With its high scalability , and much lower power consumption and higher density than bipolar junction transistors, the MOSFET made it possible to build high-density integrated circuits. The MOSFET is also capable of handling higher power than the JFET. The MOSFET was the first truly compact transistor that could be miniaturised and mass-produced for a wide range of uses. The MOSFET thus became
7370-480: The diagram, is the distance between source and drain. The width is the extension of the transistor, in the direction perpendicular to the cross section in the diagram (i.e., into/out of the screen). Typically the width is much larger than the length of the gate. A gate length of 1 μm limits the upper frequency to about 5 GHz, 0.2 μm to about 30 GHz. The names of the terminals refer to their functions. The gate terminal may be thought of as controlling
7480-460: The drain and source is controlled by the voltage applied between the gate and source. As the gate–source voltage ( V GS ) is increased, the drain–source current ( I DS ) increases exponentially for V GS below threshold, and then at a roughly quadratic rate: ( I DS ∝ ( V GS − V T ) , where V T is the threshold voltage at which drain current begins) in the " space-charge-limited " region above threshold. A quadratic behavior
7590-438: The drain and source. FETs are also known as unipolar transistors since they involve single-carrier-type operation. That is, FETs use either electrons (n-channel) or holes (p-channel) as charge carriers in their operation, but not both. Many different types of field effect transistors exist. Field effect transistors generally display very high input impedance at low frequencies. The most widely used field-effect transistor
7700-417: The drain-to-source current to remain relatively fixed, independent of changes to the drain-to-source voltage, quite unlike its ohmic behavior in the linear mode of operation. Thus, in saturation mode, the FET behaves as a constant-current source rather than as a resistor, and can effectively be used as a voltage amplifier. In this case, the gate-to-source voltage determines the level of constant current through
7810-457: The external field was blocked at the surface because of extra electrons which are drawn to the semiconductor surface. Electrons become trapped in those localized states forming an inversion layer. Bardeen's hypothesis marked the birth of surface physics . Bardeen then decided to make use of an inversion layer instead of the very thin layer of semiconductor which Shockley had envisioned in his FET designs. Based on his theory, in 1948 Bardeen patented
7920-580: The family of Eugene Tamm, a civil engineer, and his wife Olga Davydova. According to Russian sources, Tamm had German noble descent on his father's side through his grandfather Theodor Tamm, who emigrated from Thuringia . Although his surname " Tamm " is rather common in Estonia , other sources state he was Jewish or had Jewish ancestry. He studied at a gymnasium in Elisavetgrad (now Kropyvnytskyi , Ukraine ). In 1913–1914 he studied at
8030-463: The first planar transistors, in which drain and source were adjacent at the same surface. They showed that silicon dioxide insulated, protected silicon wafers and prevented dopants from diffusing into the wafer. After this, J.R. Ligenza and W.G. Spitzer studied the mechanism of thermally grown oxides, fabricated a high quality Si/ SiO 2 stack and published their results in 1960. Following this research, Mohamed Atalla and Dawon Kahng proposed
8140-447: The flow of electrons (or electron holes ) from the source to drain by affecting the size and shape of a "conductive channel" created and influenced by voltage (or lack of voltage) applied across the gate and source terminals. (For simplicity, this discussion assumes that the body and source are connected.) This conductive channel is the "stream" through which electrons flow from source to drain. In an n-channel "depletion-mode" device,
8250-454: The following limitations: Transistors are categorized by Hence, a particular transistor may be described as silicon, surface-mount, BJT, NPN, low-power, high-frequency switch . Convenient mnemonic to remember the type of transistor (represented by an electrical symbol ) involves the direction of the arrow. For the BJT , on an n-p-n transistor symbol, the arrow will " N ot P oint i N" . On
8360-409: The gate and cause unintentional switching. FET circuits can therefore require very careful layout and can involve trades between switching speed and power dissipation. There is also a trade-off between voltage rating and "on" resistance, so high-voltage FETs have a relatively high "on" resistance and hence conduction losses. Field-effect transistors are relatively robust, especially when operated within
8470-450: The idea of a field-effect transistor that used an electric field as a "grid" was not new. Instead, what Bardeen, Brattain, and Shockley invented in 1947 was the first point-contact transistor . To acknowledge this accomplishment, Shockley, Bardeen and Brattain jointly received the 1956 Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect". Shockley's team initially attempted to build
8580-418: The inventions of the junction transistor in 1948 and the MOSFET in 1959. The MOSFET is by far the most widely used transistor, in applications ranging from computers and electronics to communications technology such as smartphones . It has been considered the most important transistor, possibly the most important invention in electronics, and the device that enabled modern electronics. It has been
8690-466: The linear mode. The naming convention of drain terminal and source terminal is somewhat arbitrary, as the devices are typically (but not always) built symmetrical from source to drain. This makes FETs suitable for switching analog signals between paths ( multiplexing ). With this concept, one can construct a solid-state mixing board , for example. FET is commonly used as an amplifier. For example, due to its large input resistance and low output resistance, it
8800-613: The mechanical encoding from punched metal cards. The first prototype pocket transistor radio was shown by INTERMETALL, a company founded by Herbert Mataré in 1952, at the Internationale Funkausstellung Düsseldorf from August 29 to September 6, 1953. The first production-model pocket transistor radio was the Regency TR-1 , released in October 1954. Produced as a joint venture between
8910-425: The most common type of transistor in computers, electronics, and communications technology (such as smartphones ). The US Patent and Trademark Office calls it a "groundbreaking invention that transformed life and culture around the world". In 1948, Bardeen and Brattain patented the progenitor of MOSFET, an insulated-gate FET (IGFET) with an inversion layer. Their patent and the concept of an inversion layer, forms
9020-927: The most numerously produced artificial objects in history, with more than 13 sextillion manufactured by 2018. Although several companies each produce over a billion individually packaged (known as discrete ) MOS transistors every year, the vast majority are produced in integrated circuits (also known as ICs , microchips, or simply chips ), along with diodes , resistors , capacitors and other electronic components , to produce complete electronic circuits. A logic gate consists of up to about 20 transistors, whereas an advanced microprocessor , as of 2022, may contain as many as 57 billion MOSFETs. Transistors are often organized into logic gates in microprocessors to perform computation. The transistor's low cost, flexibility and reliability have made it ubiquitous. Transistorized mechatronic circuits have replaced electromechanical devices in controlling appliances and machinery. It
9130-425: The most significant research ideas in the semiconductor program". After Bardeen's surface state theory the trio tried to overcome the effect of surface states. In late 1947, Robert Gibney and Brattain suggested the use of electrolyte placed between metal and semiconductor to overcome the effects of surface states. Their FET device worked, but amplification was poor. Bardeen went further and suggested to rather focus on
9240-419: The neutron has a non-zero magnetic moment, the idea was met with scepticism at that time, as the neutron was supposed to be an elementary particle with zero charge, and thus could not have a magnetic moment. The same year, Tamm coined an idea that proton-neutron interactions can be described as an exchange force transmitted by a yet unknown massive particle, this idea was later developed by Hideki Yukawa into
9350-468: The ohmic or linear region, even where drain current is not approximately linear with drain voltage. Even though the conductive channel formed by gate-to-source voltage no longer connects source to drain during saturation mode, carriers are not blocked from flowing. Considering again an n-channel enhancement-mode device, a depletion region exists in the p-type body, surrounding the conductive channel and drain and source regions. The electrons which comprise
9460-404: The opening and closing of a physical gate. This gate permits electrons to flow through or blocks their passage by creating or eliminating a channel between the source and drain. Electron-flow from the source terminal towards the drain terminal is influenced by an applied voltage. The body simply refers to the bulk of the semiconductor in which the gate, source and drain lie. Usually the body terminal
9570-548: The potential in this, and over the next few months worked to greatly expand the knowledge of semiconductors . The term transistor was coined by John R. Pierce as a contraction of the term transresistance . According to Lillian Hoddeson and Vicki Daitch, Shockley proposed that Bell Labs' first patent for a transistor should be based on the field-effect and that he be named as the inventor. Having unearthed Lilienfeld's patents that went into obscurity years earlier, lawyers at Bell Labs advised against Shockley's proposal because
9680-485: The preprint of their article in December 1956 to all his senior staff, including Jean Hoerni . In 1955, Ian Munro Ross filed a patent for a FeFET or MFSFET. Its structure was like that of a modern inversion channel MOSFET, but ferroelectric material was used as a dielectric/insulator instead of oxide. He envisioned it as a form of memory, years before the floating gate MOSFET . In February 1957, John Wallmark filed
9790-503: The progenitor of MOSFET, an insulated-gate FET (IGFET) with an inversion layer. The inversion layer confines the flow of minority carriers, increasing modulation and conductivity, although its electron transport depends on the gate's insulator or quality of oxide if used as an insulator, deposited above the inversion layer. Bardeen's patent as well as the concept of an inversion layer forms the basis of CMOS technology today. In 1976 Shockley described Bardeen's surface state hypothesis "as one of
9900-405: The resistance of the transistor in the "on" state is too small to affect circuitry, and the transition between the two states is fast enough not to have a detrimental effect. In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises, the emitter and collector currents rise exponentially. The collector voltage drops because of reduced resistance from
10010-421: The surface of silicon wafer with a layer of silicon dioxide . They showed that oxide layer prevented certain dopants into the silicon wafer, while allowing for others, thus discovering the passivating effect of oxidation on the semiconductor surface. Their further work demonstrated how to etch small openings in the oxide layer to diffuse dopants into selected areas of the silicon wafer. In 1957, they published
10120-429: The temperature and electrical limitations defined by the manufacturer (proper derating ). However, modern FET devices can often incorporate a body diode . If the characteristics of the body diode are not taken into consideration, the FET can experience slow body diode behavior, where a parasitic transistor will turn on and allow high current to be drawn from drain to source when the FET is off. The most commonly used FET
10230-409: The transistor so that it operates between its cut-off region in the off-state and the saturation region ( on ). This requires sufficient base drive current. As the transistor provides current gain, it facilitates the switching of a relatively large current in the collector by a much smaller current into the base terminal. The ratio of these currents varies depending on the type of transistor, and even for
10340-483: The transistor, the company rushed to get its "transistron" into production for amplified use in France's telephone network, filing his first transistor patent application on August 13, 1948. The first bipolar junction transistors were invented by Bell Labs' William Shockley, who applied for patent (2,569,347) on June 26, 1948. On April 12, 1950, Bell Labs chemists Gordon Teal and Morgan Sparks successfully produced
10450-486: The triode. He filed identical patents in the United States in 1926 and 1928. However, he did not publish any research articles about his devices nor did his patents cite any specific examples of a working prototype. Because the production of high-quality semiconductor materials was still decades away, Lilienfeld's solid-state amplifier ideas would not have found practical use in the 1920s and 1930s, even if such
10560-435: The vast majority of FETs are electrically symmetrical. The source and drain terminals can thus be interchanged in practical circuits with no change in operating characteristics or function. This can be confusing when FET's appear to be connected "backwards" in schematic diagrams and circuits because the physical orientation of the FET was decided for other reasons, such as printed circuit layout considerations. The FET controls
10670-403: The voltage at which it occurs is called the "pinch-off voltage". Conversely, a positive gate-to-source voltage increases the channel size and allows electrons to flow easily (see right figure, when there is a conduction channel and current is large). In an n-channel "enhancement-mode" device, a conductive channel does not exist naturally within the transistor, and a positive gate-to-source voltage
10780-408: The widespread adoption of transistor radios. Seven million TR-63s were sold worldwide by the mid-1960s. Sony's success with transistor radios led to transistors replacing vacuum tubes as the dominant electronic technology in the late 1950s. The first working silicon transistor was developed at Bell Labs on January 26, 1954, by Morris Tanenbaum . The first production commercial silicon transistor
10890-415: The work of William Shockley , John Bardeen and Walter Brattain . Shockley independently envisioned the FET concept in 1945, but he was unable to build a working device. The next year Bardeen explained his failure in terms of surface states . Bardeen applied the theory of surface states on semiconductors (previous work on surface states was done by Shockley in 1939 and Igor Tamm in 1932) and realized that
11000-522: Was a Soviet physicist who received the 1958 Nobel Prize in Physics , jointly with Pavel Alekseyevich Cherenkov and Ilya Mikhailovich Frank , for their 1934 discovery and demonstration of Cherenkov radiation . He also predicted the quasi-particle of sound: the phonon ; and in 1951, together with Andrei Sakharov , proposed the Tokamak system . Igor Tamm was born in 1895 in Vladivostok into
11110-525: Was a few ten-thousandths of an inch thick. Indium electroplated into the depressions formed the collector and emitter. AT&T first used transistors in telecommunications equipment in the No. 4A Toll Crossbar Switching System in 1953, for selecting trunk circuits from routing information encoded on translator cards. Its predecessor, the Western Electric No. 3A phototransistor , read
11220-486: Was announced by Texas Instruments in May 1954. This was the work of Gordon Teal , an expert in growing crystals of high purity, who had previously worked at Bell Labs. The basic principle of the field-effect transistor (FET) was first proposed by physicist Julius Edgar Lilienfeld when he filed a patent for a device similar to MESFET in 1926, and for an insulated-gate field-effect transistor in 1928. The FET concept
11330-521: Was developed by Chrysler and Philco corporations and was announced in the April 28, 1955, edition of The Wall Street Journal . Chrysler made the Mopar model 914HR available as an option starting in fall 1955 for its new line of 1956 Chrysler and Imperial cars, which reached dealership showrooms on October 21, 1955. The Sony TR-63, released in 1957, was the first mass-produced transistor radio, leading to
11440-465: Was expected by the rest of the community. The western scientists visited the experiment and verified the high temperatures and confinement, sparking a wave of optimism for the prospects of the tokamak as well as construction of new experiments, which is still the dominant magnetic confinement device today. In 1964 he was elected a Member of the German Academy of Sciences Leopoldina . Tamm was
11550-468: Was first demonstrated in 1984 by Electrotechnical Laboratory researchers Toshihiro Sekigawa and Yutaka Hayashi. FinFET (fin field-effect transistor), a type of 3D non-planar multi-gate MOSFET, originated from the research of Digh Hisamoto and his team at Hitachi Central Research Laboratory in 1989. FETs can be majority-charge-carrier devices, in which the current is carried predominantly by majority carriers, or minority-charge-carrier devices, in which
11660-862: Was independently invented by physicists Herbert Mataré and Heinrich Welker while working at the Compagnie des Freins et Signaux Westinghouse , a Westinghouse subsidiary in Paris . Mataré had previous experience in developing crystal rectifiers from silicon and germanium in the German radar effort during World War II . With this knowledge, he began researching the phenomenon of "interference" in 1947. By June 1948, witnessing currents flowing through point-contacts, he produced consistent results using samples of germanium produced by Welker, similar to what Bardeen and Brattain had accomplished earlier in December 1947. Realizing that Bell Labs' scientists had already invented
11770-555: Was involved in the Soviet thermonuclear bomb project ; in 1949–1953 he spent most of his time in the "secret city" of Sarov , working as a head of the theoretical group developing the hydrogen bomb, however he retired from the project and returned to the Moscow Lebedev Physical Institute after the first successful test of a hydrogen bomb in 1953. In 1951, together with Andrei Sakharov , Tamm proposed
11880-455: Was later also theorized by engineer Oskar Heil in the 1930s and by William Shockley in the 1940s. In 1945 JFET was patented by Heinrich Welker . Following Shockley's theoretical treatment on JFET in 1952, a working practical JFET was made in 1953 by George C. Dacey and Ian M. Ross . In 1948, Bardeen and Brattain patented the progenitor of MOSFET at Bell Labs, an insulated-gate FET (IGFET) with an inversion layer. Bardeen's patent, and
11990-521: Was made by Dawon Kahng and Simon Sze in 1967. In 1967, Bell Labs researchers Robert Kerwin, Donald Klein and John Sarace developed the self-aligned gate (silicon-gate) MOS transistor, which Fairchild Semiconductor researchers Federico Faggin and Tom Klein used to develop the first silicon-gate MOS integrated circuit . A double-gate MOSFET was first demonstrated in 1984 by Electrotechnical Laboratory researchers Toshihiro Sekigawa and Yutaka Hayashi. The FinFET (fin field-effect transistor),
12100-451: Was theorized as a potential alternative to junction transistors, but researchers were unable to build working IGFETs, largely due to the troublesome surface state barrier that prevented the external electric field from penetrating into the material. By the mid-1950s, researchers had largely given up on the FET concept, and instead focused on bipolar junction transistor (BJT) technology. The foundations of MOSFET technology were laid down by
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