SiGe and SiGeC surface alloy formation using high dose implantation and solid phase epitaxy

SiGe is a promising alloy system for VLSI technology. In this study, surface SiGe and SiGeC alloys were formed using high-dose germanium and carbon implantation and subsequent solid phase epitaxial growth (SPEG). RBS channeling spectra and cross-sectional TEM studies show that high quality SiGe and SiGeC alloys were formed with germanium concentration up to 8 at.%, while extended defects were formed in the alloys with 16 at.% germanium. X-ray diffraction experiments show that carbon reduces the lattice strain in SiGe alloys. However, no significant crystallinity improvement was observed under RBS channeling spectra or XTEM observations. Excessive carbon dose also introduces polycrystalline layer formation. Deep level states were found in carbon implanted wafers using temperature dependent Hall effect measurements.