Selective epitaxial growth of Si1−xGex/Si strained-layers in a tubular hot-wall low pressure chemical vapor deposition system

Abstract

Selective epitaxial growth (SEG) of SiGe on patterned-oxide silicon substrates, using a tubular hot-wall low pressure chemical vapor deposition (LPCVD) system, has been demonstrated. This conventional LPCVD system was proposed as a low cost alternative for SiGe epitaxial growth. Dichlorosilane (SiH2Cl2) and germane (GeH4) were used as the reactant gases with hydrogen as a carrier gas, with no addition of HCl needed to achieve selectivity in quality epitaxial growth of SiGe. Nomarski microscopy showed good selectivity with no nucleation occurring on the SiO2 areas. A low defect silicon buffer layer grown under SEG conditions was key in obtaining high-quality growth. Cross-sectional transmission electron microscopy showed that the SiGe strained layers grown at 700 °C, 750 °C, and 800 °C were of high quality.