Interaction and ohmic contact between NiCr alloy and a-Si:H thin films at low temperatures

An array of transfer length mode (TLM) structures were designed and made on electrically isolated phosphourous -doped hydrogenated amorphous silicon (a-Si:H) thin films. Annealing effects on NiCr/a-Si:H contacts in the temperature rang from 100 degC to 400degC were studied. Electrical measurements were performed to characterize the interaction of the contact between NiCr alloy and doped a-Si:H thin films. It is found that the specific contact resistance decreases with elevated annealing temperatures. Annealing of NiCr/a-Si:H contacts at 400degC in N2 leads to a lower specific contact resistance of 4.15 Omegaldrcm2 due to good adhesion of the NiCr/a-Si:H interface. The NiCr/a-Si:H contacts could not be scratched with a tungsten carbide scriber, nor delaminated from the a-Si:H substrate.