Strain relaxation of the In0.53Ga0.47As epi-layer grown on a Si substrate using molecular beam epitaxy

Abstract

In_0.53Ga_0.47As films were grown on a Si (111) substrate with two different In_xGa_1−xAs buffer layers using molecular beam epitaxy (MBE). The effect of buffer layer on the as-grown In_0.53Ga_0.47As epi-layers was investigated using X-ray diffraction (XRD), reciprocal space mapping (RSM), Raman and transmission electron microscopy (TEM). XRD results showed that the crystalline quality of the as-grown In_0.53Ga_0.47As epi-layer grown on the Si substrate, using a low-temperature In_0.4Ga_0.6As buffer layer with in situ annealing, was better than that grown using In_0.2Ga_0.8As/In_0.4Ga_0.6As buffer layers. Moreover, the misfit strain between the In_0.53Ga_0.47As epi-layers and the Si substrate was nearly completely released by inserting a single In_0.4Ga_0.6As buffer layer grown at 390 °C with in situ annealing at 560 °C. Specifically, the relaxation value of the In_0.53Ga_0.47As epi-layer with the single In_0.4Ga_0.6As buffer layer was 97.16%. The lattice mismatch strain of the In_0.53Ga_0.47As epi-layer was well confined to the In_0.4Ga_0.6As buffer layer, without being extended to the subsequently grown In_0.53Ga_0.47As epi-layer compared with its counterpart using the In_0.2Ga_0.8As/In_0.4Ga_0.6As buffer layers. The low-temperature In_0.4Ga_0.6As buffer layer shows a way to realize fully relaxed In_0.53Ga_0.47As films with a high crystalline quality on the Si substrate.