Mechanical stability of ultrathin GeSi film on Si O2: The effect of SiSi O2 interface

Abstract

We perform two-dimensional linear elastic finite element analysis to investigate the mechanical stability of ultrathin GeSi film grown on or bonded to Si O2, using imperfect interface elements between Si and Si O2 to model SiSi O2 interfacial slippage. We demonstrate that the overall composite film is stable when only the tangential slippage is allowed, however, it becomes unstable when normal slippage is allowed: the coherently strained Ge island induces a large local bending of Si layer, and separates the Si layer from the underlying Si O2 forming a void at the SiSi O2 interface. © 2005 American Institute of Physics.