High-quality surface passivation of low-resistivity p-type C-Si by hydrogenated amorphous silicon nitride deposited by industrial-scale microwave PECVD

Abstract

High-quality surface passivation is realized with plasma silicon nitride films deposited dynamically in an industrial microwave-powered plasma-enhanced chemical vapor deposition reactor. For low-resistivity p-Si wafers symmetrically passivated by as-deposited nearly-stoichiometric (n = 2.05) nitride films, we reach effective carrier lifetimes of up to 800 μs, increasing to up to 1800 μs for samples passivated by silicon-rich nitride films (n = 2.5). This corresponds to excellent surface recombination velocities of less than 14 and 4 cm/s, respectively, assuming a bulk carrier lifetime of 3.38 ms. Such levels of silicon surface passivation with plasma silicon nitride have previously only been possible with static laboratory systems.