View source for Copper silicide

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 442611707
| ImageFile =
| ImageSize =
| IUPACName =
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 12159-07-8
| ChemSpiderID = 29356049
| EINECS =  235-286-8
| PubChem = 6336988
| StdInChI=1S/5Cu.Si
| StdInChIKey = JUZTWRXHHZRLED-UHFFFAOYSA-N
| SMILES = [Si].[Cu].[Cu].[Cu].[Cu].[Cu]
}}
|Section2={{Chembox Properties
| Formula = Cu<sub>5</sub>Si
| MolarMass = 345.8155 g/mol
| Appearance = silver powder
| Density =
| MeltingPtC = 825
| BoilingPt =
| Solubility =
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
| PEL = TWA 1 mg/m<sup>3</sup> (as Cu)<ref name=PGCH>{{PGCH|0150}}</ref>
| REL = TWA 1 mg/m<sup>3</sup> (as Cu)<ref name=PGCH/>
| IDLH =  TWA 100 mg/m<sup>3</sup> (as Cu)<ref name=PGCH/>
}}
}}

'''Copper silicide''' can refer to either {{chem2|Cu4Si}}<ref>[[CRC Handbook of Chemistry and Physics]], 49th edition, "Physical constants of inorganic compounds" (p. B-198).</ref> or pentacopper silicide, {{chem2|Cu5Si}}.

Pentacopper silicide is a [[binary compound of silicon]] with [[copper]]. It is an [[intermetallic compound]], meaning that it has properties intermediate between an [[ionic compound]] and an [[alloy]]. This solid crystalline material is a silvery solid that is insoluble in water.  It forms upon heating mixtures of copper and silicon.

==Applications==
Copper silicide [[thin film]] is used for [[Passivation (chemistry)|passivation]] of [[copper interconnects]], where it serves to suppress [[diffusion]] and [[electromigration]] and serves as a [[diffusion barrier]].<ref>{{cite web |url=http://www.patentstorm.us/patents/6869873.html |title=Copper silicide passivation for improved reliability - US Patent 6869873 |accessdate=2007-02-10 |url-status=dead |archiveurl=https://web.archive.org/web/20070929082943/http://www.patentstorm.us/patents/6869873.html |archivedate=2007-09-29 }}</ref>{{Better source needed|reason=The existence of a patented technology does not mean that it is used.|date=January 2019}}

Copper silicides are invoked in the [[Direct process]], the industrial route to [[organosilicon compounds]].  In this process, copper, in the form of its silicide, catalyses the addition of [[methyl chloride]] to silicon. An illustrative reaction affords the industrially useful [[dimethyldichlorosilane]]:<ref>{{Greenwood&Earnshaw2nd}}</ref>
:2 CH<sub>3</sub>Cl + Si → (CH<sub>3</sub>)<sub>2</sub>SiCl<sub>2</sub>

==References==
<references />

{{Copper compounds}}
{{Silicides}}

[[Category:Copper compounds]]
[[Category:Transition metal silicides]]


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