Copper silicide

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Copper silicide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.032.066 Edit this at Wikidata
EC Number
  • 235-286-8
  • InChI=1S/5Cu.Si
    Key: JUZTWRXHHZRLED-UHFFFAOYSA-N
  • [Si].[Cu].[Cu].[Cu].[Cu].[Cu]
Properties
Cu5Si
Molar mass 345.8155 g/mol
Appearance silver powder
Melting point 825 °C (1,517 °F; 1,098 K)
Hazards
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m3 (as Cu)[1]
REL (Recommended)
TWA 1 mg/m3 (as Cu)[1]
IDLH (Immediate danger)
TWA 100 mg/m3 (as Cu)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Copper silicide can refer to either Cu4Si[2] or pentacopper silicide, 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[edit]

Copper silicide thin film is used for passivation of copper interconnects, where it serves to suppress diffusion and electromigration and serves as a diffusion barrier.[3][better source needed]

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:[4]

2 CH3Cl + Si → (CH3)2SiCl2

References[edit]

  1. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ CRC Handbook of Chemistry and Physics, 49th edition, "Physical constants of inorganic compounds" (p. B-198).
  3. ^ "Copper silicide passivation for improved reliability - US Patent 6869873". Archived from the original on 2007-09-29. Retrieved 2007-02-10.
  4. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.