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 spectrometr y in a H-2 parallel-plate RF discharge, Variations of H density near t he surface in steady-state discharge conditions reveal different surfa ce loss probabilities gamma on stainless steel, hydrogenated amorphous silicon (a-Si:H) and oxidized silicon. Absolute gamma values are obta ined from time-resolved H density measurements in afterglow. The etchi ng 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.