Dipolar interactions between unpaired Si bonds at the (111)Si/SiO2 interface

Direct experimental evidence for the dipolar interactions within the two-di mensional P-b defect system at the Si/SiO2 interface is provided by the obs ervation of anisotropy in the electron spin resonance spectra. This observa tion was enabled through distinct interface degradation by post-oxidation a nnealing in H-2, leading to enhanced P-b density. The data are interpreted within the framework of a computational model based on the magnetostatic ap proximation of the local field. The results suggest P-b defects to exhibit a self-avoiding behaviour and confirm their occurrence as related to the re lease of interface stress. (C) 1999 Elsevier Science S.A. All rights reserv ed.