METASTABLE DEFECT CREATION AND ANNEALING UNDER ILLUMINATION IN INTRINSIC HYDROGENATED AMORPHOUS-SILICON DEPOSITED FROM HELIUM SILANE MIXTURES

We have investigated in detail the creation and annealing kinetics of metastable defects under illumination up to equilibrium in intrinsic d evice-quality hydrogenated amorphous silicon films deposited at a high rate using helium dilution of silane. The carrier generation rate G a s well as the light-soaking temperature T have been varied in order to study their respective influences on degradation and recovery rates a nd on the steady-state defect density N-ss. The experimental results s how that the annealing rate is increased under illumination although o ur films have a weaker dependence of N-ss on G and T than in films dep osited with pure silane. These results are discussed in the light of a simple phenomenological model which has already been successful in de scribing metastable phenomena in standard samples. Satisfactory Ms to the kinetics are obtained as well as quantitative information about th e main parameters of our rate equation.