Raman Spectroscopic Study on Silicon Films Prepared by Catalytic Chemical Vapor Deposition

Silicon films have been prepared by catalytic chemical vapor deposition (Cat-CVD), which is often called hot-wire CVD. Raman spectroscopy is very important to study silicon films. We have quantified the crystallinity of the silicon films using the intensity ratio Xc=I~520cm-1/(I~480cm-1+I~520cm-1) by deconvoluting the transverse optical (TO) phonon peak into a sharp peak around 520cm-1 and a broad band at 480cm-1 due to crystalline and amorphous phase, respectively. Effect of the temperature of substrate (Ts), distance between the filament and substrate (Lfs) and the pressure of deposition process (P) on the silicon films have been investigated from the Raman spectra, respectively (Fig.1). When increase the Ts, decrease the Lfs, or increase the P, silicon films with higher crystallinity can be obtained controllably. The changes of the deposition parameters produce different gas-phase precursors for the films and the surface dynamics has been adjusted during the film growth.