Pseudomorphic Sic Alloys Formed By Ge Ion Implantation

Pseudomorphic-strained layers containing from 0.07-1.25 atomic % Ge were formed by ion implantation at 1000 degreesC into 4H-SiC substrates. X-ray diffraction revealed high crystalline quality and coherent interfaces for strains up to 1.4%. Infrared reflectivity indicated a phonon mode at 948 cm(-1), attributed to Ge implantation disorder. Annealing above 1250 degreesC caused the disappearance of the 948 cm(-1) disorder mode, and the strengthening of the phonon mode at 848 cm(-1), associated with the 4H stacking sequence. Structural measurements of the annealed samples revealed thermally stable, coherently strained layers of the 4H polytype, without precipitation, suggesting an isoelectronic Ge alloy compatible with SiC for heterostructure strained layer engineering. (C) 2004 American Institute of Physics.