Editing Chemical vapor deposition (section)

=== Metals ===
Tungsten CVD, used for forming conductive contacts, vias, and plugs on a semiconductor device,<ref>{{Cite web|title=ALTUS Product Family|url=https://www.lamresearch.com/product/altus-product-family/|access-date=2021-04-21|website=Lam Research|language=en-US}}</ref> is achieved from [[tungsten hexafluoride]] (WF<sub>6</sub>), which may be deposited in two ways:

:WF<sub>6</sub> → W + 3 F<sub>2</sub>
:WF<sub>6</sub> + 3 H<sub>2</sub> → W + 6 HF

Other metals, notably aluminium and [[copper]], can be deposited by CVD. {{As of|2010}}, commercially cost-effective CVD for copper did not exist, although volatile sources exist, such as Cu([[hexafluoroacetylacetone|hfac]])<sub>2</sub>. Copper is typically deposited by [[electroplating]]. Aluminium can be deposited from [[triisobutylaluminium]] (TIBAL) and related [[organoaluminium compound]]s.

CVD for [[molybdenum]], [[tantalum]], [[titanium]], nickel is widely used.<ref>{{Cite web |title=Chemical Vapour Deposition - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/engineering/chemical-vapour-deposition |access-date=2022-10-20 |website=www.sciencedirect.com}}</ref> These metals can form useful [[silicide]]s when deposited onto silicon. Mo, Ta and Ti are deposited by LPCVD, from their pentachlorides. Nickel, molybdenum, and tungsten can be deposited at low temperatures from their carbonyl precursors. In general, for an arbitrary metal ''M'', the chloride deposition reaction is as follows:

:2 MCl<sub>5</sub> + 5 H<sub>2</sub> → 2 M + 10 HCl

whereas the carbonyl decomposition reaction can happen spontaneously under thermal treatment or acoustic cavitation and is as follows:

:M(CO)<sub>n</sub> → M + n CO

the decomposition of metal carbonyls is often violently precipitated by moisture or air, where oxygen reacts with the metal precursor to form metal or metal oxide along with carbon dioxide.

[[Niobium(V) oxide]] layers can be produced by the thermal decomposition of [[niobium(V) ethoxide]] with the loss of [[diethyl ether]]<ref>{{cite journal | doi =  10.1149/1.2059247 | title =  Electrochromic Properties of Niobium Oxide Thin Films Prepared by Chemical Vapor Deposition | year =  1994 | last1 =  Maruyama | first1 =  Toshiro | journal =  Journal of the Electrochemical Society | volume =  141 | issue =  10 | pages =  2868–2871| bibcode = 1994JElS..141.2868M }}</ref><ref>{{cite thesis | title = Atomic Layer Deposition of High Permittivity Oxides: Film Growth and In Situ Studies |  author = Rahtu, Antti | publisher = University of Helsinki | year = 2002 | isbn = 952-10-0646-3| hdl = 10138/21065 }}</ref> according to the equation:

:2 Nb(OC<sub>2</sub>H<sub>5</sub>)<sub>5</sub> → Nb<sub>2</sub>O<sub>5</sub> + 5 C<sub>2</sub>H<sub>5</sub>OC<sub>2</sub>H<sub>5</sub>