Strain characterization of CoSi2/n-Si0.9Ge0.1/p-Si heterostructures

We report on the structural characterization of CoSi2/n-Si0.9Ge0.1/p-Si heterostructures. Silicon molecular beam epitaxy is combined with Co sputtering to obtain these structures. The strain in the Si1−xGex is investigated after the formation of the CoSi2 by using high-resolution x-ray diffraction mapping in reciprocal space and cross-sectional transmission electron microscopy. The results show that in order to keep the strain in Si1−xGex unaffected, a sacrificial Si layer is needed. It was possible to obtain transistor action, but with low-current gain (β).