Influence of RF power on c-Si surface passivation by amorphous a-SiCX:H layers deposited by PECVD

Surface passivation of p-type crystalline silicon (c-Si) wafers has been achieved by depositing phosphorus-doped amorphous silicon carbide films (a-SiCx:H) in a PECVD reactor. We explored the dependence of effective surface recombination velocity (S-eff) on the RF power supplied to the reactor during film deposition. The effective lifetime (tau(eff)) as a function of excess carrier concentration (An) was measured by Quasi Steady State-Photoconductance (QSS-PC) technique in order to extract the surface recombination rate. We fitted the experimental tau(eff)(Delta n) curve by an insulator/semiconductor model resulting in the determination of the fixed charge density at the interface (Qf) and the fundamental recombination velocity of holes (S-p0). Additional experiments to determine the uniformity of the films along the PECVD reactor plate were carried out.