Copper silicide can refer to either or pentacopper silicide, . Pentacopper silicide is a binary compound of silicon with

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

. It is an intermetallic compound, meaning that it has properties intermediate between an

ionic compound In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (Cation, cations) and negatively charged ions (Anion, anions), which results in a compound with no net electric charge (electrica ...

and an

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

. 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 A thin film is a layer of materials ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ...

is used for passivation of copper interconnects, where it serves to suppress

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

and

electromigration Electromigration is the transport of material caused by the gradual movement of the ions in a Conductor (material), conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applicat ...

and serves as a diffusion barrier. Copper silicides are invoked in the Direct process, the industrial route to

organosilicon compounds Organosilicon chemistry is the study of organometallic compounds containing carbon–silicon bonds, to which they are called organosilicon compounds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, fl ...

. In this process, copper, in the form of its silicide, catalyses the addition of

methyl chloride Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula . One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in indus ...

to silicon. An illustrative reaction affords the industrially useful dimethyldichlorosilane: :2 CH₃Cl + Si → (CH₃)₂SiCl₂

References

Copper compounds Transition metal silicides {{inorganic-compound-stub