MOS integrated circuit, also known as MOS IC or MOS chip, is an integrated circuit chip that integrates a large number of MOS transistors. The metal–oxide–semiconductor field-effect transistor (MOSFET) is the most widely used type of transistor and the most critical device component in IC chips.[1] First proposed by Mohamed M. Atalla in 1960, the integration of large numbers of tiny MOS transistors into a small chip results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The MOS IC's mass production capability, reliability, and building-block approach to integrated circuit design has ensured the rapid adoption of standardized MOS ICs in place of designs using discrete transistors, leading to the MOS revolution in modern electronics.
MOS integrated circuits were made possible by the invention of the MOS transistor and technological advancements in metal–oxide–silicon (MOS) semiconductor device fabrication technology. Since their origins in the 1960s, the size, speed, and capacity of MOS chips have progressed enormously, driven by technical advances that fit more and more MOS transistors on chips of the same size – a modern chip may have many billions of MOS transistors in an area the size of a human fingernail. These advances, roughly following Moore's law, make computer chips of today possess millions of times the capacity and thousands of times the speed of the computer chips of the early 1970s.
The monolithic integrated circuit chip was enabled by the surface passivation process, which electrically stabilized silicon surfaces via thermal oxidation, making it possible to fabricate monolithic integrated circuit chips using silicon. The surface passivation process was developed by Mohamed M. Atalla at Bell Labs in 1957. This was the basis for the planar process, developed by Jean Hoerni at Fairchild Semiconductor in early 1959, which was critical to the invention of the monolithic integrated circuit chip by Robert Noyce later in 1959.[2][3][4] The same year,[5] Atalla used his surface passivation process to invent the MOSFET with Dawon Kahng at Bell Labs.[6][7] This was followed by the development of clean rooms to reduce contamination to levels never before thought necessary, and coincided with the development of photolithography[8] which, along with surface passivation and the planar process, allowed circuits to be made in few steps.
Mohamed Atalla realised that the main advantage of a MOS transistor was its ease of fabrication, particularly suiting it for use in the recently invented integrated circuits. He first proposed the MOS integrated cicuit (MOS IC) chip in 1960.[9] In contrast to bipolar transistors which required a number of steps for the p–n junction isolation of transistors on a chip, MOSFETs required no such steps but could be easily isolated from each other.[10] Its advantage for integrated circuits was re-iterated by Dawon Kahng in 1961.[11] The Si–SiO2 system possessed the technical attractions of low cost of production (on a per circuit basis) and ease of integration. These two factors, along with its rapidly scaling miniaturization and low energy consumption, led to the MOSFET becoming the most widely used type of transistor in IC chips.
An experimental 16-transistor MOS IC chip was demonstrated at RCA in 1962.[12]General Microelectronics later introduced the first commercial MOS integrated circuits in 1964, consisting of 120 p-channel transistors,[13] a 20-bit shift register.[12][14] In 1967, Bell Labs developed the self-aligned gate (silicon-gate) MOS transistor, which Fairchild Semiconductor researchers Federico Faggin and Tom Klein used to develop the first silicon-gate MOS IC.[15]
Importance[]
The MOS transistor forms the basis of modern electronics,[16] and is the basic element in most modern electronic equipment.[17]MOSFET scaling and miniaturization (see List of semiconductor scale examples) have been the primary factors behind the rapid exponential growth of electronic semiconductor technology since the 1960s,[18] as the rapid miniaturization of MOSFETs has been largely responsible for the increasing transistor density, increasing performance and decreasing power consumption of integrated circuit chips and electronic devices since the 1960s.[19]
MOSFET scaling and miniaturization has been driving the rapid exponential growth of electronic semiconductor technology since the 1960s, and enable high-densityintegrated circuits (ICs) such as memory chips and microprocessors. MOS integrated circuits are the primary elements of computer processors, semiconductor memory, image sensors, and most other types of integrated circuits. MOS ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.
MOS IC chips[]
There are various different types of MOS IC chips, which include the following.[20]
With its high scalability,[32] and much lower power consumption and higher density than bipolar junction transistors,[33] the MOSFET made it possible to build high-density IC chips.[34] By 1964, MOS chips had reached higher transistor density and lower manufacturing costs than bipolar chips. MOS chips further increased in complexity at a rate predicted by Moore's law, leading to large-scale integration (LSI) with hundreds of MOSFETs on a chip by the late 1960s.[35] MOS technology enabled the integration of more than 10,000 transistors on a single LSI chip by the early 1970s,[36] before later enabling very large-scale integration (VLSI).[37][38]
The MOSFET is the basis of every microprocessor,[39] and was responsible for the invention of the microprocessor.[40] The origins of both the microprocessor and the microcontroller can be traced back to the invention and development of MOS technology. The application of MOS LSI chips to computing was the basis for the first microprocessors, as engineers began recognizing that a complete computer processor could be contained on a single MOS LSI chip.[35]
The earliest microprocessors were all MOS chips, built with MOS LSI circuits. The first multi-chip microprocessors, the Four-Phase Systems AL1 in 1969 and the Garrett AiResearchMP944 in 1970, were developed with multiple MOS LSI chips. The first commercial single-chip microprocessor, the Intel 4004, was developed by Federico Faggin, using his silicon-gate MOS IC technology, with Intel engineers Marcian Hoff and Stan Mazor, and Busicom engineer Masatoshi Shima.[41] With the arrival of CMOS microprocessors in 1975, the term "MOS microprocessors" began to refer to chips fabricated entirely from PMOS logic or fabricated entirely from NMOS logic, contrasted with "CMOS microprocessors" and "bipolar bit-slice processors".[42]
Complementary metal–oxide–semiconductor (CMOS) logic[44] was developed by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963.[45] CMOS had lower power consumption, but was initially slower than NMOS, which was more widely used for computers in the 1970s. In 1978, Hitachi introduced the twin-well CMOS process, which allowed CMOS to match the performance of NMOS with less power consumption. The twin-well CMOS process eventually overtook NMOS as the most common semiconductor manufacturing process for computers in the 1980s.[46] By the 1970s–1980s, CMOS logic consumed over 7times less power than NMOS logic,[46] and about 100,000 times less power than bipolar transistor-transistor logic (TTL).[47]
Digital[]
The growth of digital technologies like the microprocessor has provided the motivation to advance MOSFET technology faster than any other type of silicon-based transistor.[48] A big advantage of MOSFETs for digital switching is that the oxide layer between the gate and the channel prevents DC current from flowing through the gate, further reducing power consumption and giving a very large input impedance. The insulating oxide between the gate and channel effectively isolates a MOSFET in one logic stage from earlier and later stages, which allows a single MOSFET output to drive a considerable number of MOSFET inputs. Bipolar transistor-based logic (such as TTL) does not have such a high fanout capacity. This isolation also makes it easier for the designers to ignore to some extent loading effects between logic stages independently. That extent is defined by the operating frequency: as frequencies increase, the input impedance of the MOSFETs decreases.
Analog[]
Further information: CMOS amplifier and Mixed-signal integrated circuit
The MOSFET's advantages in digital circuits do not translate into supremacy in all analog circuits. The two types of circuit draw upon different features of transistor behavior. Digital circuits switch, spending most of their time either fully on or fully off. The transition from one to the other is only of concern with regards to speed and charge required. Analog circuits depend on operation in the transition region where small changes to Vgs can modulate the output (drain) current. The JFET and bipolar junction transistor (BJT) are preferred for accurate matching (of adjacent devices in integrated circuits), higher transconductance and certain temperature characteristics which simplify keeping performance predictable as circuit temperature varies.
Nevertheless, MOSFETs are widely used in many types of analog circuits because of their own advantages (zero gate current, high and adjustable output impedance and improved robustness vs. BJTs which can be permanently degraded by even lightly breaking down the emitter-base). The characteristics and performance of many analog circuits can be scaled up or down by changing the sizes (length and width) of the MOSFETs used. By comparison, in bipolar transistors the size of the device does not significantly affect its performance. MOSFETs' ideal characteristics regarding gate current (zero) and drain-source offset voltage (zero) also make them nearly ideal switch elements, and also make switched capacitor analog circuits practical. In their linear region, MOSFETs can be used as precision resistors, which can have a much higher controlled resistance than BJTs. In high power circuits, MOSFETs sometimes have the advantage of not suffering from thermal runaway as BJTs do. Also, MOSFETs can be configured to perform as capacitors and gyrator circuits which allow op-amps made from them to appear as inductors, thereby allowing all of the normal analog devices on a chip (except for diodes, which can be made smaller than a MOSFET anyway) to be built entirely out of MOSFETs. This means that complete analog circuits can be made on a silicon chip in a much smaller space and with simpler fabrication techniques. MOSFETS are ideally suited to switch inductive loads because of tolerance to inductive kickback.
Some ICs combine analog and digital MOSFET circuitry on a single mixed-signal integrated circuit, making the needed board space even smaller. This creates a need to isolate the analog circuits from the digital circuits on a chip level, leading to the use of isolation rings and silicon on insulator (SOI). Since MOSFETs require more space to handle a given amount of power than a BJT, fabrication processes can incorporate BJTs and MOSFETs into a single device. Mixed-transistor devices are called bi-FETs (bipolar FETs) if they contain just one BJT-FET and BiCMOS (bipolar-CMOS) if they contain complementary BJT-FETs. Such devices have the advantages of both insulated gates and higher current density.
Bluetoothdongle. RF CMOSmixed-signal integrated circuits are widely used in nearly all modern Bluetooth devices.[49]
In the late 1980s, Asad Abidi pioneered RF CMOS technology, which uses MOS VLSI circuits, while working at UCLA. This changed the way in which RF circuits were designed, away from discrete bipolar transistors and towards CMOS integrated circuits. As of 2008, the radio transceivers in all wireless networking devices and modern mobile phones are mass-produced as RF CMOS devices. RF CMOS is also used in nearly all modern Bluetooth and wireless LAN (WLAN) devices.[49]
MOS memory[]
Main article: MOS memory
Further information: Computer memory and Memory cell (computing)
DDR4SDRAMdual in-line memory module (DIMM). It is a type of DRAM (dynamic random-access memory), which uses MOS memory cells consisting of MOSFETs and MOS capacitors.
The advent of the MOSFET enabled the practical use of MOS transistors as memory cell storage elements, a function previously served by magnetic cores in computer memory. The first modern computer memory was introduced in 1965, when John Schmidt at Fairchild Semiconductor designed the first MOS semiconductor memory, a 64-bit MOS SRAM (static random-access memory).[50] SRAM became an alternative to magnetic-core memory, but required six MOS transistors for each bit of data.[51]
MOS technology is the basis for DRAM (dynamic random-access memory). In 1966, Dr. Robert H. Dennard at the IBMThomas J. Watson Research Center was working on MOS memory. While examining the characteristics of MOS technology, he found it was capable of building capacitors, and that storing a charge or no charge on the MOS capacitor could represent the 1 and 0 of a bit, while the MOS transistor could control writing the charge to the capacitor. This led to his development of a single-transistor DRAM memory cell.[51] In 1967, Dennard filed a patent under IBM for a single-transistor DRAM (dynamic random-access memory) memory cell, based on MOS technology.[52] MOS memory enabled higher performance, was cheaper, and consumed less power, than magnetic-core memory, leading to MOS memory overtaking magnetic core memory as the dominant computer memory technology by the early 1970s.[53]
Frank Wanlass, while studying MOSFET structures in 1963, noted the movement of charge through oxide onto a gate. While he did not pursue it, this idea would later become the basis for EPROM (erasable programmable read-only memory) technology.[54] In 1967, Dawon Kahng and Simon Sze proposed that floating-gate memory cells, consisting of floating-gate MOSFETs (FGMOS), could be used to produce reprogrammable ROM (read-only memory).[55] Floating-gate memory cells later became the basis for non-volatile memory (NVM) technologies including EPROM, EEPROM (electrically erasable programmable ROM) and flash memory.[56]
Main articles: Image sensor, Charge-coupled device, and Active-pixel sensor
CMOS image sensor. MOS image sensors are the basis for digital cameras, digital imaging, camera phones, action cameras,[69] and optical mouse devices.[70]
MOS IC technology is the basis for modern image sensors, including the charge-coupled device (CCD) and the CMOS active-pixel sensor (CMOS sensor), used in digital imaging and digital cameras.[71]Willard Boyle and George E. Smith developed the CCD in 1969. While researching the MOS process, they realized that an electric charge was the analogy of the magnetic bubble and that it could be stored on a tiny MOS capacitor. As it was fairly straightforward to fabricate a series of MOS capacitors in a row, they connected a suitable voltage to them so that the charge could be stepped along from one to the next.[71] The CCD is a semiconductor circuit that was later used in the first digital video cameras for television broadcasting.[72]
The MOS active-pixel sensor (APS) was developed by Tsutomu Nakamura at Olympus in 1985.[73] The CMOS active-pixel sensor was later developed by Eric Fossum and his team at NASA's Jet Propulsion Laboratory in the early 1990s.[74]
MOS image sensors are widely used in optical mouse technology. The first optical mouse, invented by Richard F. Lyon at Xerox in 1980, used a 5µmNMOS sensor chip.[75][76] Since the first commercial optical mouse, the IntelliMouse introduced in 1999, most optical mouse devices use CMOS sensors.[70]
↑Lamba, V.; Engles, D.; Malik, S. S.; Verma, M. (2009). "Quantum transport in silicon double-gate MOSFET". 2009 2nd International Workshop on Electron Devices and Semiconductor Technology: 1–4. doi:10.1109/EDST.2009.5166116. ISBN978-1-4244-3831-0.
↑ 21.021.1Grant, Duncan Andrew; Gowar, John (1989). Power MOSFETS: theory and applications. Wiley. p. 1. ISBN9780471828679. https://books.google.com/books?id=ZiZTAAAAMAAJ. "The metal–oxide–semiconductor field-effect transistor (MOSFET) is the most commonly used active device in the very-large-scale integration of digital integrated circuits (VLSI). During the 1970s these components revolutionized electronic signal processing, control systems and computers."
↑Grant, Duncan Andrew; Gowar, John (1989). Power MOSFETS: theory and applications. Wiley. p. 1. ISBN9780471828679. https://books.google.com/books?id=ZiZTAAAAMAAJ. "The metal–oxide–semiconductor field-effect transistor (MOSFET) is the most commonly used active device in the very-large-scale integration of digital integrated circuits (VLSI). During the 1970s these components revolutionized electronic signal processing, control systems and computers."
↑Powers, E.; Zimmermann, M. (1968). TADIM—A Digital Implementation of a Multichannel Data Modem. International Conference on Communications. IEEE. p. 706. With the advent of digital microelectronic integrated circuits and MOS FET shift register memories the application of "wholesale" technology to the implementation of a digital multichannel modem became extremely attractive for providing the advantages of extremely small size, light weight, high reliability and low cost, in addition to the inherent stability and freedom from adjustment provided by digital circuitry.{{cite conference}}:
↑Boyle, William S; Smith, George E. (1970). "Charge Coupled Semiconductor Devices". Bell Syst. Tech. J.49 (4): 587–593. doi:10.1002/j.1538-7305.1970.tb01790.x.
↑Matsumoto, Kazuya et al. (1985). "A new MOS phototransistor operating in a non-destructive readout mode". Japanese Journal of Applied Physics24 (5A): L323. Bibcode1985JaJAP..24L.323M. doi:10.1143/JJAP.24.L323.
↑Eric R. Fossum (1993), "Active Pixel Sensors: Are CCD's Dinosaurs?" Proc. SPIE Vol. 1900, p. 2–14, Charge-Coupled Devices and Solid State Optical Sensors III, Morley M. Blouke; Ed.
