The formation mechanism of globally biaxial strain in He+ implanted silicon-on-insulator wafer based on the plastic deformation and smooth sliding of buried SiO2 film

Abstract

In this paper, we proposed an approach to obtain a globally biaxially strained silicon-on-insulator (SOI) wafer, and the strain mechanism was discussed. By this process, both biaxially tensile and compressive strained SOI (sSOI) can be obtained. The strain introduced into the SOI layer is mainly contributed by the plastic deformation of the buried SiO2 film caused by annealing with the deposition of a high-stress SiN film. Furthermore, He+ implantation at the interface between SiO2 and the substrate Si layer is confirmed to effectively enhance the strain by the sliding of the buried SiO2 at the SiO2-substrate Si interface. Raman spectroscopy shows that the strain of the He+ implanted sSOI has a significant enhancement of more than 300% compared with the unimplanted sSOI.