Effect of total pressure on the uniformity of epitaxial GaAs films grown in the Ga-HCl-AsH3-H2 system
The effect of total system pressure on the uniformity of epitaxial GaAs layers grown at 1023 K in the LP-VPE system has been studied with respect to layer thickness and dopant uptake. It was found that the uniformity of both of these quantities is distinctly improved when the hydrogen pressure is lowered from 3.3×104 to 6.5×l03 Pa. This behaviour is explained by the increase in gas phase diffusivity and the reduction in depletion of the gas phase during GaAs growth at reduced total pressure.