Editing CMOS (section)

{{short description|Technology for constructing integrated circuits}}
{{Other uses}}

[[File:CMOS inverter.svg|thumb|CMOS inverter (a [[Inverter (logic gate)|NOT logic gate]])]]

'''Complementary metal–oxide–semiconductor''' ('''CMOS''', pronounced "sea-moss
", {{IPAc-en|s|iː|m|ɑː|s}}, {{IPAc-en|-|ɒ|s}}) is a type of [[MOSFET|metal–oxide–semiconductor field-effect transistor]] (MOSFET) [[semiconductor device fabrication|fabrication process]] that uses complementary and symmetrical pairs of [[p-type semiconductor|p-type]] and [[n-type semiconductor|n-type]] MOSFETs for logic functions.<ref>{{cite web |title=What is CMOS Memory? |url=http://wickedsago.blogspot.com/2011/04/what-is-cmos-memory.html |work=Wicked Sago |access-date=3 March 2013 |url-status=live |archive-url=https://web.archive.org/web/20140926064548/http://wickedsago.blogspot.com/2011/04/what-is-cmos-memory.html |archive-date=26 September 2014 }}</ref> CMOS technology is used for constructing [[integrated circuit]] (IC) chips, including [[microprocessor]]s, [[microcontroller]]s, [[memory chip]]s (including [[Nonvolatile BIOS memory|CMOS BIOS]]), and other [[digital logic]] circuits. CMOS technology is also used for [[analog circuit]]s such as [[image sensor]]s ([[CMOS sensor]]s), [[data conversion|data converters]], [[RF circuit]]s ([[RF CMOS]]), and highly integrated [[transceiver]]s for many types of communication.

In 1948, Bardeen and Brattain patented an insulated-gate transistor (IGFET) with an inversion layer. Bardeen's concept forms the basis of CMOS technology today. The CMOS process was presented by [[Fairchild Semiconductor]]'s [[Frank Wanlass]] and [[Chih-Tang Sah]] at the [[International Solid-State Circuits Conference]] in 1963. Wanlass later filed [[s:United States patent 3356858|US patent 3,356,858]] for CMOS circuitry and it was granted in 1967. [[RCA|{{Tooltip|RCA|Radio Corporation of America, now a defunct American electronics company established in 1919}}]] commercialized the technology with the trademark "COS-MOS" in the late 1960s, forcing other manufacturers to find another name, leading to "CMOS" becoming the standard name for the technology by the early 1970s. CMOS overtook [[NMOS logic]] as the dominant MOSFET fabrication process for [[very large-scale integration]] (VLSI) chips in the 1980s, also replacing earlier [[transistor–transistor logic]] (TTL) technology. CMOS has since remained the standard fabrication process for MOSFET [[semiconductor device]]s in VLSI chips. {{As of|2011}}, 99% of IC chips, including most [[digital electronics|digital]], [[analog integrated circuit|analog]] and [[mixed-signal]] ICs, were fabricated using CMOS technology.<ref>{{cite book |last1=Voinigescu |first1=Sorin |title=High-Frequency Integrated Circuits |date=2013 |publisher=[[Cambridge University Press]] |isbn=9780521873024 |page=164 |url=https://books.google.com/books?id=71dHe1yb9jgC&pg=PA164}}</ref>

Two important characteristics of CMOS devices are high [[electronic noise|noise immunity]] and low static [[power consumption]].<ref>
Fairchild.
Application Note 77.
[https://www.fairchildsemi.com/application-notes/AN/AN-77.pdf "CMOS, the Ideal Logic Family"] {{webarchive|url=https://web.archive.org/web/20150109070537/https://www.fairchildsemi.com/application-notes/AN/AN-77.pdf |date=2015-01-09 }}.
1983.
</ref>
Since one [[transistor]] of the MOSFET pair is always off, the series combination draws significant power only momentarily during switching between on and off states. Consequently, CMOS devices do not produce as much [[waste heat]] as other forms of logic, like [[NMOS logic]] or [[transistor–transistor logic]] (TTL), which normally have some standing current even when not changing state. These characteristics allow CMOS to integrate a high density of logic functions on a chip. It was primarily for this reason that CMOS became the most widely used technology to be implemented in VLSI chips.

The phrase "metal–oxide–semiconductor" is a reference to the physical structure of MOS [[field-effect transistor]]s, having a [[metal gate]] electrode placed on top of an oxide insulator, which in turn is on top of a [[semiconductor|semiconductor material]]. [[Aluminium]] was once used but now the material is [[polysilicon]]. Other metal gates have made a comeback with the advent of [[high-κ dielectric]] materials in the CMOS process, as announced by IBM and Intel for the [[45 nanometer]] node and smaller sizes.<ref>{{cite web|url=http://www.intel.com/technology/45nm/index.htm|title=Intel Architecture Leads the Microarchitecture Innovation Field|website=Intel|access-date=2 May 2018|url-status=live|archive-url=https://web.archive.org/web/20110629140302/http://www.intel.com/technology/45nm/index.htm|archive-date=29 June 2011}}</ref>