Study of the relaxation of strain in patterned Si/SiGe structures using an x-ray diffraction technique

We present an investigation of a series of samples with strained stripe-patterned SiGe layers grown on a Si substrate. The strain in the SiGe striped epilayers was calculated after measuring the lattice constants of the layers using an x-ray diffraction technique. It was found that the stripes showed an anisotropic strain in the two in-plane directions resulting from the lattice mismatch and the difference in the dimensions of the stripes. The idea is based on the concept of enhancing the hole mobility in subsequent Si cap layers due to anisotropy of the stain in the patterned SiGe layers.