Low-dislocation relaxed SiGe grown on an effective compliant substrate

Strained state of the layer system depending on the SiGe layer thickness by micro-Raman mapping

“…It was speculated that the point defects introduced in the LT-Si favor the nucleation of dislocations and the trapping of propagating dislocations, as well as strain adjustment [9]. Recently, Luo et al [10] investigated the strain adjusting mechanism of the LT-Si buffer using atomic force microscopy (AFM), photoluminescence (PL) and high-resolution X-ray diffraction (HRXRD), and confirmed that the LT-Si buffer became tensily strained and reduced the lattice mismatch between the SiGe and Si buffer layer, which is similar to that of compliant substrate: a thin substrate that shares the mismatch strain in heteroepitaxy [11]. Based on the published reports, the mismatch strain is concentrated in the LT-Si layer rather than the SiGe layer and relaxes to form misfit dislocations.…”

Computer simulation of the vacancy defects interaction with shuffle dislocation in silicon

“…These dislocations lead to a poor device performance. Several methods have been used to grow high quality strainrelaxed SiGe films, such as graded composition [5], compliant substrate [6], and growth on patterned substrate [7], etc. Some prior experimental studies indicate that the use of low temperature (LT) buffer layers could significantly reduce the threading dislocation density in the SiGe layer [8][9][10].…”