The post-hydrogenation of low-pressure chemical vapor deposited amorphous silicon

Abstract Amorphous silicon films prepared by low pressure chemical vapor deposition were exposed to atomic hydrogen in an rf plasma. Concentrated hydrogen and 20% hydrogen in argon was used for the plasma. The hydrogen concentration as a function of depth was measured for various process parameters with secondary ion mass spectrometry (SIMS). Hydrogenation temperatures of 250 to 400°C and exposure times from 30–120 min were used. The hydrogen surface concentration varied between 4 and 10 at%, whereby the higher values were obtained with plasma treatments in concentrated hydrogen. The fit of an error function diffusion profile to the experimentally measured SIMS concentration results in a diffusion coefficient at 400°C of D = 6 × 10 −14 cm 2 s −1 .