MOLECULAR-BEAM EPITAXY OF CRSI2 ON SI(111)

Abstract

Chromium disilicide layers have been grown on Si(111) in a commercial molecular-beam epitaxy machine. Thin layers (10 nm) exhibit two epitaxial relationships, which have been identified as CrSi2(0001)//Si(111) with CrSi2[101̄0]//Si[101̄], and CrSi2(0001)//Si(111) with CrSi2[112̄0]//Si[101̄]. The latter case represents a 30° rotation of the CrSi2 layer about the Si surface normal relative to the former case. Thick (210 nm) layers were grown by four different techniques, and the best-quality layer was obtained by codeposition of Cr and Si at an elevated temperature. These layers are not single crystal; the largest grains are observed in a layer grown at 825 °C and are 1–2 μm across.