Raman studies of structural order in amorphous silicon-boron alloys

Abstract A new amorphous Si 1- x B x alloy with composition of boron x ranging from 0.01 to 0.5 was produced in a low pressure chemical vapor deposition (LPCVD) system. We performed Raman scattering experiments on the a - Si 1- x B x alloys and specifically monitored the Si-Si TO-like mode at around 480cm −1 and the TA-like mode at around 150cm −1 . A pronounced broadening of the TO-like band as well as a decrease of the intensity ratio I TO / I TA are observed with an increase of boron concentration in the a - Si 1- x B x alloys. Based on the Raman spectra, the mechanisms of structural changes induced by boron incorporation in the a-Si network are discussed in the conceptual framework of the continuum random network (CRN) model. We conclude that boron incorporation enhances the structural disorder.