Structural Characterization of Si1-xGex Multilayer Growth On Patterned Substrates by Very-Low-Pressure Cvd

Abstract

Strained Si 1-x Ge x multilayers were deposited heteroepitaxially at 625°C on patterned oxide Si substrates using a VLPCVD (Very-Low-Pressure Chemical Vapor Deposition) reactor. Undoped Si 1-x Ge x . layers were commensurate for Ge contents up to 23 at.% and exhibited a peak in growth rate at 8 at.% Ge. Both n-type and p-type in-situ doping were accomplished in layers having 20 at.% Ge without degradation of epitaxial quality. Arsenic and boron chemical concentrations near 10 20 cm −3 were achieved. Growth rates of in-situ doped Si 1-x Ge x . were unaffected by B 2 H 1 gas but greatly reduced by AsH 3 gas. Both undoped and in-situ doped muftilayers displayed a window-size dependence of misfit dislocations after defect etching.