Determination of thermal annealing effect in intrinsic a-Si:H film

In this study, the bias annealing effect on the density of state (DOS) in amorphous silicon film on single crystalline of silicon was investigated by means of Au/a-Si:H/c-Si/Al heterostructure. In order to fabricate the structure, at first, a-Si:H film was coated on a single crystalline silicon substrate by means of a dc magnetron sputtering technique and then gold and aluminum metal contacts were applied on the top of a-Si:H and c-Si, respectively. The samples were annealed in the annealing temperature range 110–175°C with the negative end of the applied bias voltage kept at the gold side and the capacitance–voltage characteristics heterostructure was measured. DOS around midgap of the i-region was determined by drive-level capacitance technique and the effect of thermal annealing on the DOS was indicated.