SiGe hetero MOS- and MOSFET's for ultimate scaling towards sub 100 nanometer
Virtual substrates with thin (sub 100nm) SiGe strain relaxed buffers containing 35% and 50%Ge for n-MOSFET's were elaborated. Using very low temperature growth stage and Sb surfactants, high relaxation degrees and smooth surface were achieved. Strain relaxed buffers were characterised by atomic force microscopy, X-ray diffraction, Raman spectroscopy, SIMS, optical microscopy with Nomarski contrast before and after delicate chemical etching, and TEM. The influence of layer composition and growth conditions on the degree of relaxation, surface morphology and defect formation was studied.