Mcm. Van De Sanden et al., Plasma and surface chemistry effects during high rate deposition of hydrogenated amorphous silicon, PLASMA PHYS, 41, 1999, pp. A365-A378
The plasma chemistry of an expanding thermal plasma in argon/hydrogen mixtu
res in interaction with silane is discussed. Based on Langmuir probe measur
ements and (appearance potential) mass spectrometry, it is argued that unde
r optimal conditions in terms of the a-Si:H deposited the fluxes reaching t
he growing film mainly consist of SiH3 and atomic hydrogen. The surface che
mistry, hydrogen incorporation, growth rate and dependence on substrate tem
perature are discussed and the results obtained are compared with growth mo
dels as proposed by Matsuda, Gallagher and Perrin. It is argued that althou
gh atomic hydrogen plays no role in the modification of the bulk properties
, atomic hydrogen is probably responsible for the creation of dangling bond
sites by hydrogen abstraction. Possible consequences for the substrate tem
perature dependence of the growth rate are discussed.