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134-432: A transistor 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

268-501: 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 ,

402-515: A junction field-effect transistor ( JFET ) or by an electrode insulated from the bulk material by an oxide layer, forming a metal–oxide–semiconductor field-effect transistor ( MOSFET ). The metal-oxide-semiconductor FET (MOSFET, or MOS transistor), a solid-state device, is by far the most used widely semiconductor device today. It accounts for at least 99.9% of all transistors, and there have been an estimated 13   sextillion MOSFETs manufactured between 1960 and 2018. The gate electrode

536-532: 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,

670-474: 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

804-764: 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

938-422: A clearly visible crack near the middle. However, as he moved about the room trying to test it, the detector would mysteriously work, and then stop again. After some study he found that the behavior was controlled by the light in the room – more light caused more conductance in the crystal. He invited several other people to see this crystal, and Walter Brattain immediately realized there was some sort of junction at

1072-575: 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

1206-599: 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

1340-423: 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

1474-411: A generic name for their new invention: "Semiconductor Triode", "Solid Triode", "Surface States Triode" [ sic ], "Crystal Triode" and "Iotatron" were all considered, but "transistor", coined by John R. Pierce , won an internal ballot. The rationale for the name is described in the following extract from the company's Technical Memoranda (May 28, 1948) [26] calling for votes: Transistor. This

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1608-435: 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; 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

1742-611: A nearby property. In 1928, a 15-acre (6.1 ha) site in Chester Township, New Jersey , was leased for outdoor tests, though the facility became inadequate for such purposes. In 1930, the Chester location required the purchase of an additional 85 acres (34 ha) of land to be used for a new outdoor plant development laboratory. Prior to Chester being established, a test plot was installed in Limon, Colorado in 1929, similar to

1876-420: A new branch of quantum mechanics , which became known as surface physics , to account for the behavior. The electrons in any one piece of the crystal would migrate about due to nearby charges. Electrons in the emitters, or the "holes" in the collectors, would cluster at the surface of the crystal where they could find their opposite charge "floating around" in the air (or water). Yet they could be pushed away from

2010-410: 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

2144-586: A relatively distant role with the Bell System as a whole, but continued to pursue his own personal research interests. The Bell Patent Association was formed by Alexander Graham Bell , Thomas Sanders, and Gardiner Hubbard when filing the first patents for the telephone in 1876. Bell Telephone Company, the first telephone company, was formed a year later. It later became a part of the American Bell Telephone Company. In 1884,

2278-784: A shack in Montauk, Long Island . That same year, tests were performed on the first transoceanic radio telephone at a house in Arlington County, Virginia . A radio reception laboratory was established in 1919 in the Cliffwood section of Aberdeen Township, New Jersey . Additionally for 1919, a transmission studies site was established in Phoenixville, Pennsylvania that built, in 1929, the coaxial conductor line for first tests of long-distance transmission in various frequencies. On January 1, 1925, Bell Telephone Laboratories, Inc.

2412-549: A single larger surface would serve. The electron-emitting and collecting leads would both be placed very close together on the top, with the control lead placed on the base of the crystal. When current flowed through this "base" lead, the electrons or holes would be pushed out, across the block of the semiconductor, and collect on the far surface. As long as the emitter and collector were very close together, this should allow enough electrons or holes between them to allow conduction to start. The Bell team made many attempts to build such

2546-604: 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

2680-510: A subset of devices follow those. For discrete devices , for example, there are three standards: JEDEC JESD370B in the United States, Pro Electron in Europe, and Japanese Industrial Standards (JIS). Semiconductor device fabrication is the process used to manufacture semiconductor devices , typically integrated circuits (ICs) such as computer processors , microcontrollers , and memory chips (such as RAM and Flash memory ). It

2814-449: A system with various tools but generally failed. Setups, where the contacts were close enough, were invariably as fragile as the original cat's whisker detectors had been, and would work briefly, if at all. Eventually, they had a practical breakthrough. A piece of gold foil was glued to the edge of a plastic wedge, and then the foil was sliced with a razor at the tip of the triangle. The result was two very closely spaced contacts of gold. When

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2948-658: A very small current can be achieved when the diode is reverse biased (connected with the n-side at lower electric potential than the p-side, and thus the depletion region expanded). Exposing a semiconductor to light can generate electron–hole pairs , which increases the number of free carriers and thereby the conductivity. Diodes optimized to take advantage of this phenomenon are known as photodiodes . Compound semiconductor diodes can also produce light, as in light-emitting diodes and laser diode Bipolar junction transistors (BJTs) are formed from two p–n junctions, in either n–p–n or p–n–p configuration. The middle, or base ,

3082-415: 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

3216-533: 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, the MOSFET made it possible to build high-density integrated circuits, allowing

3350-458: 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

3484-437: Is a device typically made from a single p–n junction . At the junction of a p-type and an n-type semiconductor , there forms a depletion region where current conduction is inhibited by the lack of mobile charge carriers. When the device is forward biased (connected with the p-side, having a higher electric potential than the n-side), this depletion region is diminished, allowing for significant conduction. Contrariwise, only

3618-429: Is a multiple-step photolithographic and physico-chemical process (with steps such as thermal oxidation , thin-film deposition, ion-implantation, etching) during which electronic circuits are gradually created on a wafer , typically made of pure single-crystal semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications. The fabrication process

3752-578: Is also gaining popularity in power ICs and has found some application as the raw material for blue LEDs and is being investigated for use in semiconductor devices that could withstand very high operating temperatures and environments with the presence of significant levels of ionizing radiation . IMPATT diodes have also been fabricated from SiC. Various indium compounds ( indium arsenide , indium antimonide , and indium phosphide ) are also being used in LEDs and solid-state laser diodes . Selenium sulfide

3886-524: Is an American industrial research and development (R&D) company, currently operating as a subsidiary of Finnish technology company Nokia . With a long history, Bell Labs is credited with the development of radio astronomy , the transistor , the laser , the photovoltaic cell , the charge-coupled device (CCD), information theory , the Unix operating system, and the programming languages B , C , C++ , S , SNOBOL , AWK , AMPL , and others, throughout

4020-491: Is an abbreviated combination of the words "transconductance" or "transfer", and "varistor". The device logically belongs in the varistor family, and has the transconductance or transfer impedance of a device having gain, so that this combination is descriptive. Shockley was upset about the device being credited to Brattain and Bardeen, who he felt had built it "behind his back" to take the glory. Matters became worse when Bell Labs lawyers found that some of Shockley's own writings on

4154-453: Is being studied in the manufacture of photovoltaic solar cells . The most common use for organic semiconductors is organic light-emitting diodes . All transistor types can be used as the building blocks of logic gates , which are fundamental in the design of digital circuits . In digital circuits like microprocessors , transistors act as on-off switches; in the MOSFET , for instance,

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4288-502: Is charged to produce an electric field that controls the conductivity of a "channel" between two terminals, called the source and drain . Depending on the type of carrier in the channel, the device may be an n-channel (for electrons) or a p-channel (for holes) MOSFET. Although the MOSFET is named in part for its "metal" gate, in modern devices polysilicon is typically used instead. Two-terminal devices: Three-terminal devices: Four-terminal devices: By far, silicon (Si)

4422-480: 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,

4556-421: 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

4690-446: Is performed in highly specialized semiconductor fabrication plants , also called foundries or "fabs", with the central part being the " clean room ". In more advanced semiconductor devices, such as modern 14 / 10 / 7 nm nodes, fabrication can take up to 15 weeks, with 11–13 weeks being the industry average. Production in advanced fabrication facilities is completely automated, with automated material handling systems taking care of

4824-439: Is the most widely used material in semiconductor devices. Its combination of low raw material cost, relatively simple processing, and a useful temperature range makes it currently the best compromise among the various competing materials. Silicon used in semiconductor device manufacturing is currently fabricated into boules that are large enough in diameter to allow the production of 300 mm (12 in.) wafers . Germanium (Ge)

4958-701: The American Bell Telephone Company created the Mechanical Department from the Electrical and Patent Department formed a year earlier. American Telephone & Telegraph Company (AT&T) and its own subsidiary company took control of American Bell and the Bell System by 1889. American Bell held a controlling interest in Western Electric (which was the manufacturing arm of the business) whereas AT&T

5092-571: The Number Five Crossbar Switching System . In 1952, William Gardner Pfann revealed the method of zone melting , which enabled semiconductor purification and level doping. In 1953, Maurice Karnaugh developed the Karnaugh map , used for managing of Boolean algebraic expressions. In January 1954, Bell Labs built one of the first completely transistorized computer machines, TRADIC or Flyable TRADIC, for

5226-590: The Summit, New Jersey , chemical laboratory was nearly 10 years established in a three-story building conducted experiments in corrosion, using various fungicides tests on cables, metallic components, or wood. For 1929, land was purchased in Holmdel Township, New Jersey , for a radio reception laboratory to replace the Cliffwood location that had been in operation since 1919. In 1930, the Cliffwood location

5360-444: The charge-coupled device (CCD), and many other optical, wireless, and wired communications technologies and systems. In 1924, Bell Labs physicist Walter A. Shewhart proposed the control chart as a method to determine when a process was in a state of statistical control. Shewhart's methods were the basis for statistical process control (SPC): the use of statistically based tools and techniques to manage and improve processes. This

5494-440: 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), a type of 3D non-planar multi-gate MOSFET, originated from

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5628-469: 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; the first planar transistors, in which drain and source were adjacent at

5762-402: The thermal noise in a resistor was first measured by John B. Johnson , for which Harry Nyquist provided the theoretical analysis; this is now termed Johnson-Nyquist noise . During the 1920s, the one-time pad cipher was invented by Gilbert Vernam and Joseph Mauborgne at the laboratories. Bell Labs' Claude Shannon later proved that it is unbreakable. In 1928, Harold Black invented

5896-928: The voltage applied to the gate determines whether the switch is on or off. Transistors used for analog circuits do not act as on-off switches; rather, they respond to a continuous range of inputs with a continuous range of outputs. Common analog circuits include amplifiers and oscillators . Circuits that interface or translate between digital circuits and analog circuits are known as mixed-signal circuits . Power semiconductor devices are discrete devices or integrated circuits intended for high current or high voltage applications. Power integrated circuits combine IC technology with power semiconductor technology, these are sometimes referred to as "smart" power devices. Several companies specialize in manufacturing power semiconductors. The part numbers of semiconductor devices are often manufacturer specific. Nevertheless, there have been attempts at creating standards for type codes, and

6030-694: The 20th century. Ten Nobel Prizes and five Turing Awards have been awarded for work completed at Bell Laboratories. The laboratory began in the late 19th century as the Western Electric Engineering Department, located at 463 West Street in New York City. After years of conducting research and development under Western Electric , a Bell subsidiary, the Engineering Department was reformed into Bell Telephone Laboratories in 1925 and placed under

6164-656: The Allies in World War II . The British wartime codebreaker Alan Turing visited the labs at this time, working on speech encryption and meeting Claude Shannon . Bell Labs Quality Assurance Department gave the world and the United States such statisticians as Walter A. Shewhart , W. Edwards Deming , Harold F. Dodge , George D. Edwards , Harry Romig, R. L. Jones, Paul Olmstead, E.G.D. Paterson, and Mary N. Torrey . During World War II, Emergency Technical Committee – Quality Control, drawn mainly from Bell Labs' statisticians,

6298-544: The EFEM which helps reduce the amount of humidity that enters the FOUP and improves yield. Semiconductors had been used in the electronics field for some time before the invention of the transistor. Around the turn of the 20th century they were quite common as detectors in radios , used in a device called a "cat's whisker" developed by Jagadish Chandra Bose and others. These detectors were somewhat troublesome, however, requiring

6432-453: The FOUPs into the machine. Additionally many machines also handle wafers in clean nitrogen or vacuum environments to reduce contamination and improve process control. Fabrication plants need large amounts of liquid nitrogen to maintain the atmosphere inside production machinery and FOUPs, which are constantly purged with nitrogen. There can also be an air curtain or a mesh between the FOUP and

6566-663: 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. Semiconductor device Semiconductor devices are manufactured both as single discrete devices and as integrated circuits , which consist of two or more devices—which can number from

6700-404: 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 the basis of modern digital electronics since

6834-421: 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

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6968-583: 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

7102-507: The United States Air Force with 10,358 germanium point-contact diodes and 684 Bell Labs Type 1734 Type A cartridge transistors. The design team was led by electrical engineer Jean Howard Felker with James R. Harris and Louis C. Brown ("Charlie Brown") as the lead engineers on the project, which started in 1951. The device took only 3 cubic-feet and consumed 100 watt power for its small and low powered design in comparison to

7236-612: The Voder being demonstrated at the 1939 New York World's Fair. Bell researcher Clinton Davisson shared the Nobel Prize in Physics with George Paget Thomson for the discovery of electron diffraction , which helped lay the foundation for solid-state electronics . In the early 1940s, the photovoltaic cell was developed by Russell Ohl . In 1943, Bell developed SIGSALY , the first digital scrambled speech transmission system, used by

7370-459: The Washington, D.C. home of his father, linguist Alexander Melville Bell . The carriage house there, at 1527 35th Street N.W., became their headquarters in 1889. In 1893, Bell constructed a new building close by at 1537 35th Street N.W., specifically to house the lab. This building was declared a National Historic Landmark in 1972. After the invention of the telephone, Bell maintained

7504-726: The Whippany site was purchased by Bayer ). The largest grouping of people in the company was in Illinois , at Naperville - Lisle , in the Chicago area, which had the largest concentration of employees (about 11,000) prior to 2001. There also were groups of employees in Indianapolis , Indiana; Columbus, Ohio ; North Andover, Massachusetts ; Allentown, Pennsylvania ; Reading, Pennsylvania ; and Breinigsville, Pennsylvania ; Burlington, North Carolina (1950s–1970s, moved to Greensboro 1980s) and Westminster, Colorado . Since 2001, many of

7638-412: The base-emitter current. Another type of transistor, the field-effect transistor (FET), operates on the principle that semiconductor conductivity can be increased or decreased by the presence of an electric field . An electric field can increase the number of free electrons and holes in a semiconductor, thereby changing its conductivity. The field may be applied by a reverse-biased p–n junction, forming

7772-411: The board of directors was John J. Carty , AT&T's vice president, and the first president was Frank B. Jewett , also a board member, who stayed there until 1940. The operations were directed by E. B. Craft, executive vice-president, and formerly chief engineer at Western Electric. In the early 1920s, a few outdoor facilities and radio communications development facilities were developed. In 1925,

7906-404: 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

8040-607: The center of the galaxy . In 1931 and 1932, the labs made experimental high fidelity, long playing, and even stereophonic recordings of the Philadelphia Orchestra , conducted by Leopold Stokowski . In 1933, stereo signals were transmitted live from Philadelphia to Washington, D.C. In 1937, the vocoder , an electronic speech compression device, or codec, and the Voder , the first electronic speech synthesizer , were developed and demonstrated by Homer Dudley ,

8174-436: 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

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8308-464: 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 the metal–oxide–semiconductor field-effect transistor (MOSFET),

8442-444: 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

8576-448: 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

8710-446: The crack. Further research cleared up the remaining mystery. The crystal had cracked because either side contained very slightly different amounts of the impurities Ohl could not remove – about 0.2%. One side of the crystal had impurities that added extra electrons (the carriers of electric current) and made it a "conductor". The other had impurities that wanted to bind to these electrons, making it (what he called) an "insulator". Because

8844-424: The crystal were of any reasonable size, the number of electrons (or holes) required to be injected would have to be very large, making it less than useful as an amplifier because it would require a large injection current to start with. That said, the whole idea of the crystal diode was that the crystal itself could provide the electrons over a very small distance, the depletion region. The key appeared to be to place

8978-558: 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

9112-455: 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,

9246-535: The decade. Shannon was also the founder of modern cryptography with his 1949 paper Communication Theory of Secrecy Systems . The 1950s also saw developments based upon information theory . The central development was binary code systems. Efforts concentrated on the prime mission of supporting the Bell System with engineering advances, including the N-carrier system, TD microwave radio relay , direct distance dialing , E- repeater , wire spring relay , and

9380-458: 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

9514-399: The electrons being pushed into the collector would quickly fill up the "holes" (the electron-needy impurities), and conduction would stop almost instantly. This junction of the two crystals (or parts of one crystal) created a solid-state diode, and the concept soon became known as semiconduction. The mechanism of action when the diode off has to do with the separation of charge carriers around

9648-410: The electrons from the emitter to the collector of this newly discovered diode, an amplifier could be built. For instance, if contacts are placed on both sides of a single type of crystal, current will not flow between them through the crystal. However, if a third contact could then "inject" electrons or holes into the material, the current would flow. Actually doing this appeared to be very difficult. If

9782-572: The first transatlantic communications cable to carry telephone conversations, was laid between Scotland and Newfoundland in a joint effort by AT&T, Bell Laboratories, and British and Canadian telephone companies. In 1957, Max Mathews created MUSIC , one of the first computer programs to play electronic music . Robert C. Prim and Joseph Kruskal developed new greedy algorithms that revolutionized computer network design . In 1957 Frosch and Derick, using masking and predeposition, were able to manufacture silicon dioxide field effect transistors;

9916-450: The first demonstration to higher-ups at Bell Labs on the afternoon of 23 December 1947, often given as the birthdate of the transistor. What is now known as the " p–n–p point-contact germanium transistor " operated as a speech amplifier with a power gain of 18 in that trial. John Bardeen , Walter Houser Brattain , and William Bradford Shockley were awarded the 1956 Nobel Prize in physics for their work. Bell Telephone Laboratories needed

10050-454: 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

10184-434: The former locations have been scaled down or closed. Bell's Holmdel research and development lab , a 1,900,000-square-foot (180,000 m ) structure set on 473 acres (191 ha), was closed in 2007. The mirrored-glass building was designed by Eero Saarinen . In August 2013, Somerset Development bought the building, intending to redevelop it into a mixed commercial and residential project. A 2012 article expressed doubt on

10318-407: The hundreds to the billions—manufactured and interconnected on a single semiconductor wafer (also called a substrate). Semiconductor materials are useful because their behavior can be easily manipulated by the deliberate addition of impurities, known as doping . Semiconductor conductivity can be controlled by the introduction of an electric or magnetic field, by exposure to light or heat, or by

10452-447: 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

10586-439: The input and output contacts very close together on the surface of the crystal on either side of this region. Brattain started working on building such a device, and tantalizing hints of amplification continued to appear as the team worked on the problem. Sometimes the system would work but then stop working unexpectedly. In one instance a non-working system started working when placed in water. Ohl and Brattain eventually developed

10720-465: 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 was made by Dawon Kahng and Simon Sze in 1967. In 1967, Bell Labs researchers Robert Kerwin, Donald Klein and John Sarace developed

10854-496: The junction. This is called a " depletion region ". Armed with the knowledge of how these new diodes worked, a vigorous effort began to learn how to build them on demand. Teams at Purdue University , Bell Labs , MIT , and the University of Chicago all joined forces to build better crystals. Within a year germanium production had been perfected to the point where military-grade diodes were being used in most radar sets. After

10988-549: The labs had one. After hunting one down at a used radio store in Manhattan , he found that it worked much better than tube-based systems. Ohl investigated why the cat's whisker functioned so well. He spent most of 1939 trying to grow more pure versions of the crystals. He soon found that with higher-quality crystals their finicky behavior went away, but so did their ability to operate as a radio detector. One day he found one of his purest crystals nevertheless worked well, and it had

11122-540: 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 the most numerously produced artificial objects in history, with more than 13 sextillion manufactured by 2018. Although several companies each produce over

11256-616: The later Bell Laboratories locations in New Jersey were Holmdel Township , Crawford Hill , the Deal Test Site , Freehold , Lincroft , Long Branch , Middletown , Neptune Township , Princeton , Piscataway , Red Bank , Chester Township , and Whippany . Of these, Murray Hill and Crawford Hill remain in existence (the Piscataway and Red Bank locations were transferred to and are now operated by Telcordia Technologies and

11390-401: The location performed precision frequency-measuring apparatus, field strength measurements, and conducted radio interference. By the early 1940s, Bell Labs engineers and scientists had begun to move to other locations away from the congestion and environmental distractions of New York City, and in 1967 Bell Laboratories headquarters was officially relocated to Murray Hill, New Jersey . Among

11524-428: The mechanical deformation of a doped monocrystalline silicon grid; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs due to mobile or "free" electrons and electron holes , collectively known as charge carriers . Doping a semiconductor with a small proportion of an atomic impurity, such as phosphorus or boron , greatly increases the number of free electrons or holes within

11658-799: 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 the Regency Division of Industrial Development Engineering Associates, I.D.E.A. and Texas Instruments of Dallas, Texas,

11792-564: The more reliable and amplified vacuum tube based radios, the cat's whisker systems quickly disappeared. The "cat's whisker" is a primitive example of a special type of diode still popular today, called a Schottky diode . Another early type of semiconductor device is the metal rectifier in which the semiconductor is copper oxide or selenium . Westinghouse Electric (1886) was a major manufacturer of these rectifiers. During World War II, radar research quickly pushed radar receivers to operate at ever higher frequencies about 4000 MHz and

11926-487: The negative feedback system commonly used in amplifiers. Later, Harry Nyquist analyzed Black's design rule for negative feedback. This work was published in 1932 and became known as the Nyquist criterion . In 1931, a foundation for radio astronomy was laid by Karl Jansky during his work investigating the origins of static on long-distance shortwave communications . He discovered that radio waves were being emitted from

12060-568: The one in Gulfport. The three test plots at Gulfport, Limon, and Chester were outdoor facilities for preservatives and prolonging the use of telephone poles. Additionally, in 1929, a land expansion was done at the Deal Labs to 208 acres (84 ha). This added land increased the facility for radio transmission studies. The beginning of 1930s, established three facilities with radio communications experiments and chemical aspects testing. By 1939,

12194-399: The operator to move a small tungsten filament (the whisker) around the surface of a galena (lead sulfide) or carborundum (silicon carbide) crystal until it suddenly started working. Then, over a period of a few hours or days, the cat's whisker would slowly stop working and the process would have to be repeated. At the time their operation was completely mysterious. After the introduction of

12328-545: 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

12462-439: The region between the junctions is typically very narrow. The other regions, and their associated terminals, are known as the emitter and the collector . A small current injected through the junction between the base and the emitter changes the properties of the base-collector junction so that it can conduct current even though it is reverse biased. This creates a much larger current between the collector and emitter, controlled by

12596-431: 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 the inventions of the junction transistor in 1948 and

12730-404: 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

12864-509: The result was not published until 1950. In 1948, " A Mathematical Theory of Communication ", one of the founding works in information theory , was published by Claude Shannon in the Bell System Technical Journal . It built in part on earlier work in the field by Bell researchers Harry Nyquist and Ralph Hartley , but went much further. Bell Labs also introduced a series of increasingly complex calculators through

12998-447: 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 a silicon MOS transistor in 1959 and successfully demonstrated

13132-546: The semiconductor. When a doped semiconductor contains excess holes, it is called a p-type semiconductor ( p for positive electric charge ); when it contains excess free electrons, it is called an n-type semiconductor ( n for a negative electric charge). A majority of mobile charge carriers have negative charges. The manufacture of semiconductors controls precisely the location and concentration of p- and n-type dopants. The connection of n-type and p-type semiconductors form p–n junctions . The most common semiconductor device in

13266-537: The shared ownership of Western Electric and the American Telephone and Telegraph Company (AT&T). In the 1960s, laboratory and company headquarters were moved to Murray Hill, New Jersey . Its alumni during this time include people like William Shockley , Dennis Ritchie , Claude Shannon and Willard Boyle . Bell Labs became a subsidiary of AT&T Technologies in 1984 after the Bell System

13400-464: The success of the newly named Bell Works site, but several large tenants had announced plans to move in through 2016 and 2017. Bell Lab's 1974 corporate directory listed 22 labs in the United States, located in: Nokia Bell Lab's 2024 website pictured 10 labs, located in: Also listed as research locations without additional information was Sunnyvale, California , US and Tampere, Finland . The Naperville, Illinois Bell Labs location near Chicago

13534-426: The surface with the application of a small amount of charge from any other location on the crystal. Instead of needing a large supply of injected electrons, a very small number in the right place on the crystal would accomplish the same thing. Their understanding solved the problem of needing a very small control area to some degree. Instead of needing two separate semiconductors connected by a common, but tiny, region,

13668-569: The test plot studies were established at Gulfport, Mississippi , where there were numerous telephone pole samples established for wood preservation. At the Deal, New Jersey location, work was done on ship-to-shore radio telephony. In 1926, in the Whippany section of Hanover Township, New Jersey , land was acquired and established for the development of a 50-kilowatt broadcast transmitter. In 1931, Whippany increased with 75 acres (30 ha) added from

13802-474: The traditional tube-based radio receivers no longer worked well. The introduction of the cavity magnetron from Britain to the United States in 1940 during the Tizard Mission resulted in a pressing need for a practical high-frequency amplifier. On a whim, Russell Ohl of Bell Laboratories decided to try a cat's whisker . By this point, they had not been in use for a number of years, and no one at

13936-409: 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

14070-438: The transistor were close enough to those of an earlier 1925 patent by Julius Edgar Lilienfeld that they thought it best that his name be left off the patent application. Shockley was incensed, and decided to demonstrate who was the real brains of the operation. A few months later he invented an entirely new, considerably more robust, bipolar junction transistor type of transistor with a layer or 'sandwich' structure, used for

14204-480: 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

14338-559: The transport of wafers from machine to machine. A wafer often has several integrated circuits which are called dies as they are pieces diced from a single wafer. Individual dies are separated from a finished wafer in a process called die singulation , also called wafer dicing. The dies can then undergo further assembly and packaging. Within fabrication plants, the wafers are transported inside special sealed plastic boxes called FOUPs . FOUPs in many fabs contain an internal nitrogen atmosphere which helps prevent copper from oxidizing on

14472-418: 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

14606-407: The two parts of the crystal were in contact with each other, the electrons could be pushed out of the conductive side which had extra electrons (soon to be known as the emitter ), and replaced by new ones being provided (from a battery, for instance) where they would flow into the insulating portion and be collected by the whisker filament (named the collector ). However, when the voltage was reversed

14740-470: The vacuum tube designs of the times. The device could be installed in a B-52 Stratofortress Bomber and had a performance up to one million logical operations a second. The flyable program used a Mylar sheet with punched holes, instead of the removable plugboard. In 1954, the first modern solar cell was invented at Bell Laboratories. In 1955, Carl Frosch and Lincoln Derick discovered semiconductor surface passivation by silicon dioxide. In 1956 TAT-1 ,

14874-506: The vast majority of all transistors into the 1960s. With the fragility problems solved, the remaining problem was purity. Making germanium of the required purity was proving to be a serious problem and limited the yield of transistors that actually worked from a given batch of material. Germanium's sensitivity to temperature also limited its usefulness. Scientists theorized that silicon would be easier to fabricate, but few investigated this possibility. Former Bell Labs scientist Gordon K. Teal

15008-588: The wafer diameter to sizes significantly smaller than silicon wafers thus making mass production of GaAs devices significantly more expensive than silicon. Gallium Nitride (GaN) is gaining popularity in high-power applications including power ICs , light-emitting diodes (LEDs), and RF components due to its high strength and thermal conductivity. Compared to silicon, GaN's band gap is more than 3 times wider at 3.4 eV and it conducts electrons 1,000 times more efficiently. Other less common materials are also in use or under investigation. Silicon carbide (SiC)

15142-553: The wafer. At Bell Labs, the importance of Frosch and Derick technique and transistors 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 the preprint of their article in December 1956 to all his senior staff, including Jean Hoerni , who would later invent the planar process in 1959 while at Fairchild Semiconductor . Bell Labs Bell Labs

15276-442: The wafers. Copper is used in modern semiconductors for wiring. The insides of the processing equipment and FOUPs is kept cleaner than the surrounding air in the cleanroom. This internal atmosphere is known as a mini-environment and helps improve yield which is the amount of working devices on a wafer. This mini environment is within an EFEM (equipment front end module) which allows a machine to receive FOUPs, and introduces wafers from

15410-406: The war, William Shockley decided to attempt the building of a triode -like semiconductor device. He secured funding and lab space, and went to work on the problem with Brattain and John Bardeen . The key to the development of the transistor was the further understanding of the process of the electron mobility in a semiconductor. It was realized that if there were some way to control the flow of

15544-408: The wedge was pushed down onto the surface of a crystal and voltage was applied to the other side (on the base of the crystal), current started to flow from one contact to the other as the base voltage pushed the electrons away from the base towards the other side near the contacts. The point-contact transistor had been invented. While the device was constructed a week earlier, Brattain's notes describe

15678-405: 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

15812-479: The world is the MOSFET (metal–oxide–semiconductor field-effect transistor ), also called the MOS transistor . As of 2013, billions of MOS transistors are manufactured every day. Semiconductor devices made per year have been growing by 9.1% on average since 1978, and shipments in 2018 are predicted for the first time to exceed 1 trillion, meaning that well over 7 trillion have been made to date. A semiconductor diode

15946-522: 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

16080-401: Was a widely used early semiconductor material but its thermal sensitivity makes it less useful than silicon. Today, germanium is often alloyed with silicon for use in very-high-speed SiGe devices; IBM is a major producer of such devices. Gallium arsenide (GaAs) is also widely used in high-speed devices but so far, it has been difficult to form large-diameter boules of this material, limiting

16214-481: 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

16348-464: Was broken up . After the breakup, its funding greatly declined. In 1996, AT&T Technologies was spun off and renamed to Lucent Technologies, who used the Murray Hill site as their headquarters. Bell Laboratories was split as well, with part of it going to AT&T as AT&T Laboratories . In 2006, Lucent merged with French telecommunications company Alcatel to form Alcatel-Lucent , which

16482-506: Was considered the Chicago Innovation Center and hosted Nokia's second annual Algorithm World event in 2022. Bell Laboratories was, and is, regarded by many as the premier research facility of its type, developing a wide range of revolutionary technologies, including radio astronomy , the transistor , the laser , information theory , the operating system Unix , the programming languages C and C++ , solar cells ,

16616-519: 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

16750-438: Was doing research into the service providers. In 1896, Western Electric bought property at 463 West Street to centralize the manufacturers and engineers which had been supplying AT&T with such technology as telephones, telephone exchange switches and transmission equipment. During the early 20th century, several historically significant laboratories were established. In 1915, the first radio transmissions were made from

16884-506: Was ending its operations as Holmdel was established. Whereas, in 1930, a location in Mendham Township, New Jersey , was established to continue radio receiver developments farther from the Whippany location and eliminate transmitter interference at that facility with developments. The Mendham location worked on communication equipment and broadcast receivers. These devices were used for marine, aircraft, and police services as well as

17018-779: Was in turn acquired by Nokia in 2016. In 1880, when the French government awarded Alexander Graham Bell the Volta Prize of 50,000   francs for the invention of the telephone (equivalent to about US$ 10,000 at the time, or about $ 330,000 now), he used the award to fund the Volta Laboratory (also known as the "Alexander Graham Bell Laboratory") in Washington, D.C. in collaboration with Sumner Tainter and Bell's cousin Chichester Bell . The laboratory

17152-862: 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

17286-460: Was instrumental in advancing Army and Navy ammunition acceptance and material sampling procedures. In 1947, the transistor , arguably the most important invention developed by Bell Laboratories, was invented by John Bardeen , Walter Houser Brattain , and William Bradford Shockley (who subsequently shared the Nobel Prize in Physics in 1956). In 1947, Richard Hamming invented Hamming codes for error detection and correction . For patent reasons,

17420-453: 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

17554-420: Was organized to consolidate the development and research activities in the communication field and allied sciences for the Bell System. Ownership was evenly shared between Western Electric and AT&T. The new company had 3600 engineers, scientists, and support staff. Its 400,000-square-foot (37,000 m ) space was expanded with a new building occupying about one quarter of a city block. The first chairman of

17688-478: Was the first to develop a working silicon transistor at the nascent Texas Instruments , giving it a technological edge. From the late 1950s, most transistors were silicon-based. Within a few years transistor-based products, most notably easily portable radios, were appearing on the market. " Zone melting ", a technique using a band of molten material moving through the crystal, further increased crystal purity. In 1955, Carl Frosch and Lincoln Derick accidentally grew

17822-427: Was the origin of the modern quality control movement, including Six Sigma . In 1926, the laboratories invented an early synchronous-sound motion picture system, in competition with Fox Movietone and DeForest Phonofilm . In 1927, a Bell team headed by Herbert E. Ives successfully transmitted long-distance 128-line television images of Secretary of Commerce Herbert Hoover from Washington to New York. In 1928

17956-667: Was variously known as the Volta Bureau , the Bell Carriage House , the Bell Laboratory and the Volta Laboratory . It focused on the analysis, recording, and transmission of sound. Bell used his considerable profits from the laboratory for further research and education advancing the diffusion of knowledge relating to the deaf. This resulted in the founding of the Volta Bureau ( c.  1887 ) at

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