Surface recombination probabilities of H on stainless steel, a-Si:H and oxidized silicon determined by threshold ionization mass spectrometry in H-2 RF discharges

H atom densities are measured by threshold ionization mass spectrometry in a H-2 parallel-plate RF discharge, Variations of H density near the surface in steady-state discharge conditions reveal different surface loss probabilities gamma on stainless steel, hydrogenated amorphous silicon (a-Si:H) and oxidized silicon. Absolute gamma values are obtained from time-resolved H density measurements in afterglow. The etching probability of Si per H atom incident on a-Si:H is also derived by monitoring Si-4 partial pressure and SiH(A(2) Delta) optical emission.