The reaction of oxygen with silicon and germanium at elevated temperatures by weight loss measurement

Abstract

Germanium and silicon single crystal wafers were masked with Al2O3 and SiO2 respectively on their back faces, and their clean faces held close to a cold condensing surface. They were then heated by thermal radiation in oxygen atmospheres in the pressure range 10-3 to 2 × 10-2 Torr at temperatures sufficiently high that the reaction was limited by the sticking efficiency of oxygen on the clean wafer. The sticking coefficient of oxygen on germanium was found to be 0.033 for {111} {110} and {100} orientations, with higher values for {111} at 820°C as previously reported. The sticking coefficient of oxygen on silicon was found to be in the range 0.06 to 0.11 for {111} and {100} orientations with slightly lower values observed on two {110} samples. Higher values were obtained on pitted or matte surfaces. © 1964.