Internal Dissolution of Buried Oxide in SOI Wafers

摘要

High temperature anneal of SOI wafers in oxygen-free atmosphere results in internal buried oxide dissolution and top Si layer etching. Dissolution rate is determined by interstitial oxygen diffusion through the top Si layer and evaporation from the top Si surface in the form of SiO. It has been observed that kinetics of the process follows linear-parabolic law. Simple thermodynamic model is proposed, which explains observed dependences on temperature and top Si layer thickness.