(Invited) Atomically Controlled Processing for Si and Ge CVD Epitaxial Growth

Abstract

In this work, the segregation of dopants and surface roughness generation observed during in-situ doping and their suppression by applying an atomic layer doping approach are presented. The impurity segregations are explained by the Langmuir-type adsorption and reaction scheme. Results of nm-order thick Ge epitaxial growth on Si(100) using an ultraclean low-pressure CVD system are obtained. Degradation for epitaxial growth of Si and Ge is induced by the existence of Ge oxide in the CVD reactor. It is suggested that the evaporated Ge oxide is adsorbed on the Si surface and the Ge oxide is reduced to the pure Ge by the Si in accordance with Si oxide formation and that the Ge oxide evaporation is suppressed by SiH4 treatment. These results demonstrate the capability of CVD technology for atomically controlled processing of Si, Si1-xGex and Ge for ultra large scale integration.