Improvement of the surface roughness and the electrical resistivity of polycrystallineSi1-xGex films by two step deposition and Ar/H2 plasma treatment

Abstract

Poly-Si1-xGex films were prepared on thermally oxidized Si(100) wafers using two step deposition (550 oC, 400Pa + 600 oC, 400Pa) by rapid thermal chemical vapor deposition. The deposited films were subjected to in-situ annealing and Ar/H2 plasma treated. The changes to the surface roughness, the grain size, and the electrical resistivity were investigated. The surface roughness was improved greatly by two step deposition whereas the grain size was slightly decreased. By in-situ annealing, the grain size increased up to 170 nm. Both the rms value and the resistivity decreased during Ar/H2 plasma treatment and were influenced by the surface etching effect of Ar ions and the hydrogenation effect, respectively.