Formation of high-quality and relaxed SiGe buffer layer with H-implantation and subsequent thermal annealing

Different architectures of relaxed Si1−xGex/Si pseudo-substrates grown by low-pressure chemical vapor deposition: Structural and morphological characteristics

“…2a and as already reported in [6]. No threading dislocations were observed in the SiGe layer, which implies that the low temperature Si BL is efficient in relieving the strain, and the propagation of emerging threading dislocations is partially blocked by point defects [6,8]. The threading dislocation density measured by EPC on optical microscopy images (after Schimmel etching for 15 s) is about 10 5 cm À 2 (Fig.…”

“…Thus, one must optimize the latter while having enough point-defects in the volume of the layer allowing the blocking of dislocations. ii) High temperature Si buffer layer (B 1 and B 2 samples): the same growth conditions as the previous method [6][7][8] are used, but the Si BL is deposited at high temperature (T ¼700 1C) by ultra-high vacuum (UHV) CVD to improve its crystalline quality, as displayed in Fig. 3a.…”

“…Here, we proposed to create a ductile area in the Si BL, before the SiGe deposition. It consists of nanocavities located at about 100 nm under the Si BL surface and obtained by He þ implantation at 10 keV and at room temperature with fluencies of 5 Â 10 15 ions cm À 2 or 5 Â 10 16 ions cm À 2 . The creation of the nanocavity layer is enabled by an annealing step at 700 1C for one hour.…”

“…In another approach, a Si BL was grown at high temperature (HT) by MBE or CVD [6]. In this paper, these two ways [6][7][8] are reconsidered by varying some parameters of growth by CVD.…”

“…The easiest way is to schedule the implantation before the SiGe growth step. Depending on the used ion gas and the implantation conditions [6,9,16], various types of bubbles, connected with different interfacial dislocations, were observed [17]. The interactions between bubbles and dislocations require the bubble layer to be separated from the interfacial region [18,19].…”