Observations on the formation and etching of platinum silicide

Abstract

When thin‐film platinum and single‐crystal silicon are interdiffused, [inverted lazy s] 100 Å of SiO₂ is found at the PtSi surface. The silica protects the silicide from attack by the aqua regia commonly used to remove unreacted Pt. If the silica is stripped, PtSi on Si will dissolve in aqua regia even faster than Pt. These findings are applicable to contact technology for silicon devices and integrated circuits.