Method for forming a Pt-Si Schottky barrier contact

摘要

The difference in sputter etch rate of Pt over PtSi is increased by sputter etching the Pt in an ambient of rare gas contg. =1 vol. % O2 or N2, pref. Ar contg. 10 vol. % O2. The method is incorporated in formation of a Schottky barrier electrode in an Si substrate, specifically by (a) forming active circuit elements in the Si substrate, (b) coating the surface with an insulating layer having at least one opening exposing the Si, (c) depositing a blanket layer of Pt on the insulator and in the opening, (d) sintering, forming PtSi in the opening and (e) sputter etching the uncombined Pt as above. The increased differential in etch rates results in lower Pt thinning than using pure Ar. Contamination is less, with no Cl and S contamination.