Ballistic electron transport through Au(111)/Si(111) and Au(111)/Si(100) interfaces

Ballistic electron emission microscopy (BEEM) measurements have been made, as a function of Au thickness, of Au(111)/Si(111) and Au(111)/Si(100) inter faces, fabricated and studied in ultrahigh vacuum. The measured ballistic e lectron attenuation length for Au is in excess of 230 Angstrom for both Si orientations. In accord with metal band-structure considerations, the BEEM current is consistently more than 50% higher for Si(111) than for Si(100) s ubstrates. Surface electron states have been observed on atomically flat su rfaces of the Au grains, and their presence correlated with a spatially var ying BEEM current. [S0163-1829(99)51304-0].