Optimisation des paramètres de dépôt de a-Si:H dans la technique Hg-photo-CVDK
Optimizing deposition parameters of a-Si:H in Hg-photo-CVD technology
The Hg-photo-CVD technique, known for its use in eveloping thin film of semiconductor materials and dielectrics has been a resurgence of interest in view of their many applications in microelectronics. It is established that the physico-chemical and optoelectronic material filed in this case the hydrogenated amorphous silicon (a-Si: H) are a function of preparation conditions, including substrate temperature, the pressure of reactive gases, their speed, light intensity, temperature of reaction medium, temperature of the mercury and temperature of the post-deposition annealing.
We highlight in this article which is a review of our work in this area, the conditions for optimization of key arameters of deposition : Mercury Temperature T
HG : about 50° C - substrate temperature Ts : 250 to 300 °C - Reactive gas pressure : around 1 Torr - gas flow reagent : 1 to 5 sccm (or cm3 / s) - The nominal light intensity : 10 to 20 mW/cm2, temperature of post-deposition annealing: about 300 ° C for 30 minutes. At Ts = 280 °C, the photosensitivity is optimized to a value of more than 103. In the optimal working conditions proposed, conversion of the reactive gas in silicon is streamlined and the large amount of hydrogen formed, for security reasons, become as the carrier gas for the evacuation of the gas mixture.