A STUDY OF THE EFFECTS OF ANNEALING AND OUTGASSING ON HYDROGENATED AMORPHOUS-SILICON

Annealing and outgassing of thin films of hydrogenated amorphous silic on (a-Si:H) are shown to produce major structural changes in the mater ial. Outgassing can occur in three stages with thresholds at 350 degre es C, 450 degrees C and 575 degrees C corresponding to conversion of S iH3 groups to SiH2 and SiH; conversion of SiH2 groups to Si and SiH; a nd conversion of SiH to Si respectively. Heating to 575 degrees C also appears to remove most of the hydrogen from vacancies and defects in the material. Such heat treatments could he useful for improving the s tability of thin film a-Si:H devices. (C) 1997 Elsevier Science B.V.