Defect reduction in GexSi1−x epitaxy by rapid thermal processing chemical vapor deposition using a low-temperature in situ preclean and a Si buffer layer

Abstract

For chamber base pressure ≊5×10−4 mbar in a rapid thermal processing chemical vapor deposition system, a 900 °C H2 prebake for 60 s results in relatively high defect densities in the GexSi1−x epitaxial layer due to surface damage caused by the H2 prebake. We have demonstrated that a very low thermal budget in situ preclean (800 °C/15 s) can reduce the defect densities. In addition, the use of a Si buffer layer grown at 1000 °C for 60 s prior to the GexSi1−x growth is capable of significantly reducing defect densities.