Local strain in Si/Si_0.6Ge_0.4/Si(100) heterostructures by stripe-shape patterning

In Si/Si_0.6Ge_0.4/Si(100) heterostructure patterned into stripe shape, local strain in the capping Si and Si_0.6Ge_0.4 layers was investigated. From the strain amount evaluation by Raman scattering spectroscopy using visible and ultraviolet light, relationship between the strain relaxation amount in the strained Si_0.6Ge_0.4 layer and tensile strain amount in the capping Si layer was clarified. The Raman shift change in the 5 nm-thick capping Si layer was in excellent agreement with the expected value with assumption of perfect in-plane lattice matching between the Si_0.6Ge_0.4 and capping Si layers. In the case of the thicker capping Si layer, the Raman shift change tends to be smaller than that for the 5 nm-thick capping Si layer.