A silicon nitride layer may be formed with a suitable refractive index, mass density, and hydrogen concentration so that the layer may serve as an ARC/passivation layer on a solar cell substrate. The silicon nitride layer may be formed on a solar cell substrate by adding a hydrogen gas diluent to a conventional precursor gas mixture during the deposition process. Alternatively, the silicon nitride layer may be formed on a solar cell substrate by using a precursor gas mixture consisting essentially of silane and nitrogen. To improve deposition chamber throughput, the silicon nitride layer may be a dual stack film that includes a low-hydrogen interface layer and a thicker bulk silicon nitride layer. Placing a plurality of solar cell substrates on a substrate carrier and transferring the substrate carrier into the deposition chamber may further enhance deposition chamber throughput.