Kinetics of Silicon Growth under Low Hydrogen Pressure

Abstract

The kinetics of silicon deposition have been studied in a reactor working under reduced hydrogen pressure between 10 Torr and atmospheric pressure (760 Torr) for the following silicon sources: , , , and . In every case, the kinetics are controlled by the surface at low hydrogen pressure whereas at higher pressure the mass transfer becomes slower. When the kinetics are controlled by the surface, the deposition rate is inversely proportional to the square root of the hydrogen pressure and is activated. In the opposite case the deposition rate is inversely proportional to the hydrogen pressure and does not depend on the temperature. This result, and the fact that the depositions are monocrystalline even at low temperature when the pressure is lower than 70 Torr, show that the hydrogen is strongly adsorbed on the silicon surface. The deposition made at low pressure and low temperature have abrupt impurity profiles which allow us to realize good quality microwave components.