The growth and investigation of SiGe films on buried Ge islands

SiGe/Si films on buried Ge islands on Si substrates were deposited using an ultrahigh vacuum chemical vapor deposition system at a temperature of 620 degrees C in comparison with a single-step SiGe film with the same Ge conte nt and growth temperature. X-ray diffraction measurements show that the cry stalline quality of the Sice films on the buried Ge islands was better than that without buffers, and the top SiGe films were relaxed. The high-resolu tion cross-sectional transmission electron microscopy images show that the size of the three dimension Ge islands is about 60 nm and the top SiGe film on buried Ge islands is better crystallographically than that grown withou t buffers. (C) 1999 Elsevier Science B.V. All rights reserved.