Chemical Vapor Deposition of Epitaxial Silicon‐Germanium from Silane and Germane: I . Kinetics

Abstract

We report measured germanium incorporation and growth rate for grown by very low pressure chemical vapor deposition in the temperature range of 570 to 700°C. The growth rate of shows different germanium dependencies at different temperatures. We found that the growth rate decreases at 700°C and increases at 570°C with the addition of germanium. The observed nonlinear Arrhenius behavior of the growth rate as a function of germanium content suggests that germanium modifies the activation energy for deposition, possibly by enhancing hydrogen desorption. The possible rate‐limiting steps controlling deposition were examined by varying the hydrogen flow rate and the total deposition pressure, and it was found that hydrogen suppresses deposition rate when the germanium content is low. The consistent growth‐rate enhancement observed by increasing total deposition pressure is dependent on germanium incorporation and becomes more pronounced as the germanium content is increased. A model is proposed to explain our observations.