RAMAN-SCATTERING STUDY OF MICROSTRUCTURE OF N-TYPE POROUS SILICON

We report a detailed Raman scattering study of porous silicon film pre pared on n-type silicon substrate. We observe large enhancement of Ram an scattered signal and also that with increase in laser power the Ram an line shape shows low frequency asymmetry, decrease in frequency of the peak position and reduction in signal enhancement. Our results cou ld be explained consistently only by considering a two layered model o f the microstructure of these films. We argue that this is a simple an d non-destructive technique to look at the layered nature of the micro structure of these materials - so far seen only by high resolution ele ctron microscopy. Copyright (C) Elsevier Science Ltd