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A semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material (primarily silicon , germanium , and gallium arsenide , as well as organic semiconductors ) for its function. Its conductivity lies between conductors and insulators. Semiconductor devices have replaced vacuum tubes in most applications. They conduct electric current in the solid state , rather than as free electrons across a vacuum (typically liberated by thermionic emission ) or as free electrons and ions through an ionized gas .

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83-618: Inmos International plc (trademark INMOS ) and two operating subsidiaries, Inmos Limited (UK) and Inmos Corporation (US), was a British semiconductor company founded by Iann Barron , Richard Petritz, and Paul Schroeder in July 1978. Inmos Limited’s head office and design office were at Aztec West business park in Bristol , England. Inmos' first products were static RAM devices, followed by dynamic RAMs and EEPROMs . Despite early production difficulties, Inmos eventually captured around 60% of

166-414: A cable box , receiver, or simply box , and historically television decoder or a converter , is an information appliance device that generally contains a TV tuner input and displays output to a television set , turning the source signal into content in a form that can then be displayed on the television screen or other display device . It is designed to be placed alongside or "on top" (hence

249-562: A PCMCIA -like card inserted as part of the digital signal path as their alternative to a tuner-equipped set-top box. According to the Los Angeles Times , the cost to a cable provider in the United States for a set-top box is between $ 150 for a basic box to $ 250 for a more sophisticated box. In 2016, the average pay-TV subscriber paid $ 231 per year to lease their set-top box from a cable service provider. In June 2011,

332-515: 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

415-617: A personal identification number . Some boxes simply block all channels, while others allow the user to restrict access to chosen channels not suitable for children below certain ages. As complexity and potential programming faults of the set-top box increase, software such as MythTV , Select-TV and Microsoft 's Media Center have developed features comparable to those of set-top boxes, ranging from basic DVR-like functionality to DVD copying, home automation , and housewide music or video playback. Almost all modern set-top boxes feature automatic firmware update processes. The firmware update

498-433: A satellite dish , a coaxial cable (see cable television ), a telephone line (including DSL connections), broadband over power lines (BPL), or even an ordinary VHF or UHF antenna . Content, in this context, could mean any or all of video , audio , Internet web pages , interactive video games , or other possibilities. Satellite and microwave-based services also require specific external receiver hardware, so

581-542: A Dutch consortium had been turned down. In 1982, construction of the microprocessor factory in Newport , South Wales was completed. By July 1984 Thorn EMI had made a £124.1m bid for the state's 76% interest in the company (the remaining 24% had been held by Inmos founders and employees). Later it was raised to £192 million, approved August 1984 and finalized in September. In total, Inmos had received £211 million from

664-422: 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

747-411: 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

830-435: 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

913-459: A mandated inclusion in new television sets . Some have also been produced to mute the audio (or replace it with noise) when profanity is detected in the captioning, where the offensive word is also blocked. Some also include a V-chip that allows only programs of some television content rating systems . A function that limits children's time watching TV or playing video games may also be built in, though some work on main electricity rather than

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996-420: 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

1079-677: A report from the American National Resources Defense Council brought attention to the energy efficiency of set-top boxes, and the United States Department of Energy announced plans to consider the adoption of energy efficiency standards for set-top boxes. In November 2011, the National Cable & Telecommunications Association announced a new energy efficiency initiative that commits the largest American cable operators to

1162-549: 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

1245-500: 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

1328-449: 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

1411-658: 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 ,

1494-437: 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

1577-429: 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

1660-578: 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

1743-491: 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

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1826-453: 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,

1909-555: 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)

1992-409: Is fed with the baseband television signal from the set's tuner, and can have the television display the returned processed signal instead. This SCART feature had been used for connection to analogue decoding equipment by pay-TV operators in Europe, and in the past, it was used for connection to teletext equipment before the decoders became built-in. The outgoing signal could be of the same nature as

2075-446: 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

2158-439: 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)

2241-402: Is typically provided by the service provider. With the advent of flat-panel televisions , set-top boxes are now deeper in profile than the tops of most modern TV sets. Because of this, set-top boxes are often placed beneath televisions, and the term set-top box has become something of a misnomer , possibly helping the adoption of the term digibox . Additionally, newer set-top boxes that sit at

2324-928: 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

2407-544: 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

2490-453: 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

2573-761: The US and Europe, telephone companies use IPTV (often on ADSL or optical fibre networks) as a means to compete with traditional local cable television monopolies. This type of service is distinct from streaming television , which involves third-party content over the public Internet not controlled by the local system operator. Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming. Some guides, such as ITV , also feature backward scrolling to promote their catch-up content. This feature allows

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2656-519: The air and were therefore not on standard TV receivers. Before cable-ready TV sets became common in the late 1980s, an electronic tuning device called a cable converter box was needed to receive the additional analogue cable TV channels and transpose or convert the selected channel to analogue radio frequency (RF) for viewing on a regular TV set on a single channel, usually VHF channel 3 or 4. The box allowed an analogue non–cable-ready television set to receive analogue encrypted cable channels and

2739-412: 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

2822-557: The cable head-end instead of the final viewing location. However, most cable systems could not accommodate the full 54-to-890 MHz VHF/UHF frequency range and the twelve channels of VHF space were quickly exhausted on most systems. Adding any additional channels therefore needed to be done by inserting the extra signals into cable systems on nonstandard frequencies, typically either below VHF channel 7 (midband) or directly above VHF channel 13 (superband). These frequencies corresponded to non-television services (such as two-way radio) over

2905-543: The cost of launching new services, increases speed to market, and limits disruption for consumers. As examples, Hybrid Broadcast Broadband TV (HbbTV) set-top boxes allow traditional TV broadcasts, whether from terrestrial (DTT), satellite, or cable providers, to be brought together with video delivered over the Internet and personal multimedia content. Advanced Digital Broadcast (ADB) launched its first hybrid DTT/IPTV set-top box in 2005, which provided Telefónica with

2988-446: 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

3071-424: 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

3154-526: The digital TV platform for its Movistar TV service by the end of that year. In 2009, ADB provided Europe's first three-way hybrid digital TV platform to Polish digital satellite operator n , which enables subscribers to view integrated content whether delivered via satellite, terrestrial, or internet. UK-based Inview Technology has over 8   million STBs deployed in the UK for Teletext and an original push VOD service for Top Up TV. In IPTV networks,

3237-416: The edge of IP-based distribution networks are often called net-top boxes or NTBs, to differentiate between IP and RF inputs. The Roku LT is around the size of a pack of cards and delivers Smart TV to conventional sets. The distinction between external tuner or demodulator boxes (traditionally considered to be "set-top boxes") and storage devices (such as VCR, DVD, or disc-based PVR units) is also blurred by

3320-399: 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

3403-410: 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

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3486-666: The ever-increasing performance of its competitors. Other devices produced by Inmos included the A100, A110 and A121 digital signal processors , G364 framebuffer , and a line of video RAMDACs , including the G170 and G171, which was adopted by IBM for the original VGA graphics adapter used in the IBM PS/2 . The company was founded by Iann Barron , a British computer consultant, Richard Petritz and Paul Schroeder, both American semiconductor industry veterans. Initial funding of £50 million

3569-450: 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

3652-503: The government, but did not become profitable. According to Iann Barron Inmos was profitable in 1984 "we were really profitable in 1984 ... we made revenues of £150 million, and we made a profit which was slightly less than £10 million". In April 1989, Inmos was sold to SGS-Thomson (now STMicroelectronics ). Around the same time, work was started on an enhanced transputer, the T9000. This encountered various technical problems and delays, and

3735-407: 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

3818-592: The incoming signal, or RGB component video , or even an " insert " over the original signal, due to the "fast switching" feature of SCART. In case of analogue pay-TV, this approach avoided the need for a second remote control . The use of digital television signals in more modern pay-TV schemes requires that decoding take place before the digital-to-analogue conversion step, rendering the video outputs of an analogue SCART connector no longer suitable for interconnection to decryption hardware. Standards such as DVB 's Common Interface and ATSC 's CableCARD therefore use

3901-463: The increasing deployment of satellite and cable tuner boxes with a hard disk , network or USB interfaces built-in. Devices with the capabilities of computer terminals , such as the WebTV thin client , also fall into the grey area that could invite the term "NTB". In Europe, a set-top box does not necessarily contain a tuner of its own. A box connected to a television (or VCR) SCART connector

3984-439: 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

4067-496: 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

4150-549: 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

4233-428: 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

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4316-564: 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

4399-511: The name) of a television set. Set-top boxes are used in cable television , satellite television , terrestrial television and Internet Protocol television systems, as well as other uses such as digital media players ("streaming boxes"). Alternatives to set-top boxes are the smaller dongles , or television sets with built-in TV tuners that hence won't require a separate device such as a set-top box. The signal source might be an Ethernet cable,

4482-399: 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

4565-836: The professional broadcast audio/video industry. They are designed for more robust field handling and rack mounting environments. IRDs are capable of outputting uncompressed serial digital interface signals, unlike consumer STBs which usually do not, mostly because of copyright reasons. Hybrid set-top boxes, such as those used for Smart TV programming, enable viewers to access multiple TV delivery methods (including terrestrial, cable, internet, and satellite); like IPTV boxes, they include video on demand , time-shifting TV, Internet applications, videotelephony , surveillance, gaming, shopping, TV-centric electronic program guides , and e-government. By integrating varying delivery streams, hybrids (sometimes known as "TV-centric" ) enable pay-TV operators more flexible application deployment, which decreases

4648-539: The receiver to shift a portion of the UHF-TV spectrum onto low-VHF channels for viewing. As some 1960s-era 12-channel TV sets remained in use for many years, and Canada and Mexico were slower than the US to require UHF tuners to be factory-installed in new TVs, a market for these converters continued to exist for much of the 1970s. Cable television represented a possible alternative to deployment of UHF converters as broadcasts could be frequency-shifted to VHF channels at

4731-439: 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

4814-546: 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

4897-576: The set-top box is a small computer providing two-way communications on an IP network and decoding the video streaming media . IP set-top boxes have a built-in home network interface that can be Ethernet , Wireless (802.11   g,n,ac), or one of the existing wire home networking technologies such as HomePNA or the ITU-T G.hn standard, which provides a way to create a high-speed (up to 1 Gbit/s) local area network using existing home wiring ( power lines , phone lines, and coaxial cables ). In

4980-426: 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,

5063-474: 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

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5146-438: 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

5229-559: 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

5312-407: 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

5395-556: The use of set-top boxes of various formats has never completely disappeared. Set-top boxes can also enhance source signal quality. Before the All-Channel Receiver Act of 1962 required US television receivers to be able to tune the entire VHF and UHF range (which in North America was NTSC-M channels 2 through 83 on 54 to 890   MHz ), a set-top box known as a UHF converter would be installed at

5478-692: The user is out. The user still needs to program the VCR or DVD recorder. Some models have controls on the box, as well as on the remote control . This is useful should the user lose the remote or if the batteries age. Some remote controls can also control some basic functions of various brands of TVs. This allows the user to use just one remote to turn the TV on and off, adjust volume, or switch between digital and analogue TV channels or between terrestrial and internet channels. The parental lock or content filters allow users over 18 years old to block access to channels that are not appropriate for children, using

5561-432: The user to choose preferred channels, making them easier and quicker to access; this is handy with the wide range of digital channels on offer. The concept of favourite channels is superficially similar to that of the " bookmark " function offered in many web browsers. The timer allows the user to program and enable the box to switch between channels at certain times: this is handy to record from more than one channel while

5644-506: 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

5727-555: The video signal. The transition to digital terrestrial television after the turn of the millennium left many existing television receivers unable to tune and display the new signal directly. In the United States, where the analogue shutdown was completed in 2009 for full-service broadcasters, a federal subsidy was offered for coupon-eligible converter boxes with deliberately limited capability which would restore signals lost to digital transition. Professional set-top boxes are referred to as IRDs or integrated receiver/decoders in

5810-588: 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)

5893-586: 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 . Set-top box A set-top box ( STB ), also known as

5976-442: 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

6059-406: 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

6142-408: 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

6225-578: The world SRAM market. However, Barron's long-term aim was to produce an innovative microprocessor architecture intended for parallel processing , the transputer . David May and Robert Milne were recruited to design this processor, which went into production in 1985 in the form of the T212 and T414 chips. The transputer achieved some success as the basis for several parallel supercomputers from companies such as Meiko (formed by ex-Inmos employees in 1985), Floating Point Systems , Parsytec and Parsys. It

6308-479: 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

6391-460: Was a prototype topology for later date digital encryption devices. Newer televisions were then converted to be analogue cypher cable-ready, with the standard converter built-in for selling premium television (aka pay-per-view ). Several years later and slowly marketed, the advent of digital cable continued and increased the need for various forms of these devices. Block conversion of the entire affected frequency band onto UHF , while less common,

6474-401: 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

6557-681: Was eventually abandoned, signalling the end of the development of the transputer as a parallel processing platform. However, transputer derivatives such as the ST20 were later incorporated into chipsets for embedded applications such as set-top boxes . In December 1994, Inmos was fully assimilated into STMicroelectronics, and the usage of the Inmos brand name was discontinued. 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

6640-776: Was provided by the UK government via the National Enterprise Board . A US subsidiary, Inmos Corporation, was also established in Colorado . Semiconductor fabrication facilities were built in the US at Colorado Springs, Colorado and in the UK at Newport , South Wales . Under the privatization policy of Margaret Thatcher the National Enterprise Board was merged into the British Technology Group and had to sell its shares in Inmos. Offers for Inmos from AT&T and

6723-478: 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

6806-720: Was used by some models to provide full VCR compatibility and the ability to drive multiple TV sets, albeit with a somewhat nonstandard channel numbering scheme. Newer television receivers greatly reduced the need for external set-top boxes, although cable converter boxes continue to be used to descramble premium cable channels according to carrier-controlled access restrictions, and to receive digital cable channels, along with using interactive services like video on demand , pay per view, and home shopping through television. Set-top boxes were also made to enable closed captioning on older sets in North America, before this became

6889-484: Was used in a few workstations, the most notable probably being the Atari Transputer Workstation . Being a relatively self-contained design, it was also used in some embedded systems . However, the unconventional nature of the transputer and its native occam programming language limited its appeal. During the late 1980s, the transputer (even in its later T800 form) also struggled to keep up with

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