Editing Silicon dioxide (section)

===Semiconductors===
{{See also|Surface passivation|Thermal oxidation|Planar process|MOSFET}}

Silicon dioxide is widely used in the semiconductor technology:

* for the primary passivation (directly on the semiconductor surface),
* as an original [[gate dielectric]] in [[MOS technology]]. Today when scaling (dimension of the gate length of the MOS transistor) has progressed below 10&nbsp;nm, silicon dioxide has been replaced by other [[dielectric materials]] like [[hafnium oxide]] or similar with higher dielectric constant compared to silicon dioxide,
* as a dielectric layer between metal (wiring) layers (sometimes up to 8–10) connecting elements and
* as a second passivation layer (for protecting semiconductor elements and the metallization layers) typically today layered with some other dielectrics like [[silicon nitride]].

Because silicon dioxide is a native oxide of silicon it is more widely used compared to other semiconductors like [[gallium arsenide]] or [[indium phosphide]].

Silicon dioxide could be grown on a silicon [[semiconductor]] surface.<ref name="Bassett22">{{cite book |last1=Bassett |first1=Ross Knox |title=To the Digital Age: Research Labs, Start-up Companies, and the Rise of MOS Technology |date=2007 |publisher=[[Johns Hopkins University Press]] |isbn=9780801886393 |pages=22–23 |url=https://books.google.com/books?id=UUbB3d2UnaAC&pg=PA22}}</ref> Silicon oxide layers could protect silicon surfaces during [[diffusion processes]], and could be used for diffusion masking.<ref name="Lecuyer">{{cite book |last1=Lécuyer |first1=Christophe |last2=Brock |first2=David C. |title=Makers of the Microchip: A Documentary History of Fairchild Semiconductor |date=2010 |publisher=[[MIT Press]] |isbn=9780262294324 |page=111 |url=https://books.google.com/books?id=LaZpUpkG70QC&pg=PA111}}</ref><ref name="Saxena">{{cite book |last= Saxena|first= A |title = Invention of integrated circuits: untold important facts |url = https://books.google.com/books?id=z7738Wq-j-8C |publisher = [[World Scientific]] |series = International series on advances in solid state electronics and technology |year = 2009 |isbn = 9789812814456 |pages = 96–97}}</ref>

[[Surface passivation]] is the process by which a semiconductor surface is rendered inert, and does not change semiconductor properties as a result of interaction with air or other materials in contact with the surface or edge of the crystal.<ref name="atalla">{{cite web|title=Martin Atalla in Inventors Hall of Fame, 2009|url=https://www.invent.org/inductees/martin-john-m-atalla|access-date=21 June 2013}}</ref><ref name="Black">{{cite book |last1=Black |first1=Lachlan E. |title=New Perspectives on Surface Passivation: Understanding the Si-Al2O3 Interface |date=2016 |publisher=[[Springer Science+Business Media|Springer]] |isbn=9783319325217 |page=17 |url=https://books.google.com/books?id=laYFDAAAQBAJ&pg=PA17}}</ref> The formation of a [[Thermal oxidation|thermally]] grown silicon dioxide layer greatly reduces the concentration of [[surface states|electronic states at the silicon surface]].<ref name="Black"/> SiO<sub>2</sub> [[Thin film|films]] preserve the electrical characteristics of [[p–n junction]]s and prevent these electrical characteristics from deteriorating by the gaseous ambient environment.<ref name="Saxena"/> Silicon oxide layers could be used to electrically stabilize silicon surfaces.<ref name="Lecuyer"/> The surface passivation process is an important method of [[semiconductor device fabrication]] that involves coating a [[silicon wafer]] with an insulating layer of silicon oxide so that electricity could reliably penetrate to the conducting silicon below. Growing a layer of silicon dioxide on top of a silicon wafer enables it to overcome the [[surface states]] that otherwise prevent electricity from reaching the semiconducting layer.<ref name="atalla"/><ref name="kahng">{{cite web |title=Dawon Kahng |url=https://www.invent.org/inductees/dawon-kahng |website=[[National Inventors Hall of Fame]] |access-date=27 June 2019}}</ref>

The process of silicon surface passivation by [[thermal oxidation]] (silicon dioxide) is critical to the [[semiconductor industry]]. It is commonly used to manufacture [[metal–oxide–semiconductor field-effect transistor]]s (MOSFETs) and silicon [[integrated circuit]] chips (with the [[planar process]]).<ref name="atalla"/><ref name="kahng"/>