Post-annealing effect on the a-SiCx passivation layer synthesized with the radio frequency magnetron co-sputtering method

Abstract

The amorphous silicon carbide (a-SiC) film has been considered a good candidate for the rear passivation layer of the high-efficiency silicon solar cell. We describe the results of the post-annealing of an amorphous silicon carbide (a-SiC) film deposited using the radio frequency magnetron sputtering method. The post-annealing was performed with rapid thermal annealing process in three different chamber environments: nitrogen (N2), oxygen (O2), and hydrogen (H2). After the annealing process, the characteristic properties of the films were investigated in several categories. The transmittance of the film was measured with Scinco s-3100 at the 400–800nm wavelength. The average transmittance increased after the annealing treatment, and the highest transmittance was achieved with the H2 ambient. Using a silicon wafer lifetime tester, we measured the carrier lifetime of the films. We found that the carrier lifetime was highest in the N2 ambient annealing process. Also, the refractive index was determined using an ellipsometer. The measurement indicated that the refractive index of the film decreased in the annealing process, unlike that of the as-deposited film.