The Structure of Hydrogenated Amorphous Silicon-Carbon Alloys as Investigated by Exafs

Abstract

ABSTRACTWe have studied the local structure of hydrogenated amorphous silicon-carbon alloy films, a-Si1−xCx:H, by measuring the extended x-ray absorption fine-structure (EXAFS) at the Si K edge.We find that first coordination shell average bond lengths are 2.35 Å for Si-Si and 1.86 Å for Si-C and are constant with concentration to within × 0.015 Å.By comparing the composition of the first coordination shell around Si with the average concentration we show that the alloy tends to be chemically ordered, in that heteroatomic bonds are preferred.