Electrical characteristics of metal contacts on the surfaces of a-Si:H films annealed at low temperature
The hydrogenated amorphous silicon (a-Si:H) films were deposited by a tetrode RF sputtering method and annealed at low temperature 200°C in a high grade vacuum for 120 min. Various metals were deposited on the surfaces of the annealed a-Si:H films; Schottky junctions were formed, and the current versus voltage (J-V) characteristics were measured. From the comparison with the characteristics of the metal contacts on the surfaces of the films as deposited, the remarkable effect of low temperature annealing in a vacuum on the surface of a-Si:H films was confirmed. From the experimental results, it was concluded that the low temperature annealing process appears to eliminate the dangling bonds created on the surface by ion bombardment during film deposition, and consequently decreases the density of surface states of a-Si:H films.