Thin relaxed SiGe virtual substrates grown by low-energy plasma-enhanced chemical vapor deposition

We present a method to produce thin SiGe virtual substrates suitable for electronic applications. This method is based on the gas phase process of low-energy plasma-enhanced chemical vapor deposition. The strain-relaxed buffers are characterized by X-ray diffractometry, transmission electron microscopy and atomic force microscopy. We find threading dislocation densities lower than 3×108 cm−2 and a surface rms roughness of 1.8 nm, for a buffer thickness of 500 nm. Room temperature electrical results are also presented, which are competitive with those obtained on SiGe buffers produced by other methods.