Chemical process of silicon epitaxial growth in a SiHCl 3–H 2 system

Abstract

The chemical process of silicon epitaxial growth in a SiHCl 3–H 2 system at atmospheric pressure is studied experimentally using a horizontal cold-wall single-wafer reactor and a quadrupole mass spectra analyzer. The dominant chlorosilane species in the gas phase and the dominant overall chemical reaction are experimentally determined to be SiHCl 3 gas and SiHCl 3+H 2→Si+3HCl, respectively. Since the amount of HCl gas produced in the reactor is proportional to the silicon epitaxial growth rate, it is concluded that the dominant chemical process of silicon epitaxial growth in a SiHCl 3–H 2 system occurs on the silicon substrate surface. The concentrations of SiCl 2, SiH 2Cl 2, SiHCl and SiCl 4 gases produced in the gas phase are too low to play a significant role in silicon epitaxial growth.