kopersilicium

Kopersilicium, or copper silicide, refers to a family of copper–silicon intermetallic compounds rather than a single chemical formula. These materials form when silicon reacts with copper, typically by diffusion at elevated temperatures or during deposition and subsequent annealing. In the copper–silicon system, several intermetallic phases are known, with Cu3Si being among the most commonly reported; other compositions such as Cu5Si are also observed depending on temperature and composition. The intermetallics generally exhibit limited solubility of silicon in copper and form distinct, ordered crystal structures.

Formation and properties

Copper silicides arise at copper–silicon interfaces in various processing contexts, including semiconductor device fabrication and alloying processes. They are typically hard and brittle solid phases with high thermal stability. Their electrical conductivity is lower than that of pure copper, but they can still conduct electricity; however, their mechanical brittleness and a tendency to form at interfaces influence reliability in devices. The exact properties vary with the specific intermetallic phase and microstructure.

Applications and relevance

Copper silicides are particularly relevant in microelectronics as diffusion barrier and contact materials at copper–silicon interfaces. In integrated circuits, the presence and control of copper silicide layers affect contact resistance, electromigration behavior, and diffusion of silicon. Beyond electronics, copper silicides have been studied for high-temperature coatings and as precursors in copper-based diffusion studies. Their use is balanced against brittleness and stability considerations under operating conditions.

See also

Copper–silicon phase diagram; diffusion barriers; intermetallics.