Spectroscopic studies of H-decorated interstitials and vacancies in thin-film silicon exfoliation

In this paper, we review the pivotal role that defects tin particular vacancy structures play in driving the H-2-induced exfoliation of Si. We highlight the central role that infrared spectroscopy has played in delineating the microscopic details of the exfoliation process. We show that when the results of such spectroscopic studies are combined with those obtained using a variety of other experimental probes as well as ab initio quantum chemical cluster calculations, an unambiguous mechanistic picture emerges. Specifically we find that H-2-terminated vacancy structures drive the formation of internal surfaces into cracks where Hz is then evolved, resulting in the build-up of sufficient internal pressure to cause lift-off of the overlying Si. The role of coimplantation of He is also discussed. (C) 1999 Elsevier Science B.V. All rights reserved.