Three-layer structure of hydrogenated Czochralski silicon

The depth profiles of the Si-H bonds, H-2 molecules, and hydrogen-induced platelets (HIPs) in H-plasma-treated Czochralski (CZ) silicon wafers have been investigated. In this investigation Raman spectroscopy and scanning electron microscopy are applied on a beveled sample surface. It is found that there is a three-layer structure in hydrogenated silicon samples: an H-plasma-damaged surface layer with a thickness of similar to0.2 mum, an HIP subsurface layer of similar to0.5 mum, and a transition region (with a thickness about 1 mum) between the HIP layer and the nondisturbed bulk of the wafer. This structure is confirmed by cross-sectional transmission electron microscopy. The depth profile of the H-2 molecules agrees well with that of the HIPs, confirming that the HIPs are the containers of the H-2 molecules. Based on these results, a general picture of the hydrogenation process on CZ silicon has been suggested. (C) 2004 The Electrochemical Society.