Passivation of silicon wafers by Silicon Carbide (SiCx) thin film grown by sputtering

Silicon Carbide films for silicon solar cell application were deposited by means of RF sputtering process. Films were deposited from mixed Silicon – Graphite target onto silicon Cz <100> wafers. Samples were characterized by Photo Conductance Decay (PCD) method to measure the effective lifetime. The thickness and refractive index of the films deposited were measured using a spectroscopic Ellipsometer. X-Ray Diffraction (XRD) was performed to measure the crystallinity of the samples. Results have indicated that the deposited films were mainly amorphous. The crystalline fraction was present in samples with a better passivation level. Results from PCD show that the effective lifetime improved up to 38 μs which corresponds to a Voc=641 mV. Deposition rates up to 30 nm/min were obtained for samples at 0.9 kW bias power.