Co-relation between capacitance-voltage, conductance-voltage and photoconductive properties of the as-deposited and annealed a-Si/SiNx multilayer films prepared using hot-wire CVD

In this paper, the electrical properties of the as-deposited and the annealed a-Si/SiN_x multilayer (ML) films are compared. The a-Si/SiN_x ML films are prepared at 250°C using hot-wire chemical vapor deposition (HWCVD) technique. Silicon quantum dots (Si-QDs) are formed in the a-Si layers of ML films upon annealing at 850°C. Metal insulator semiconductor (MIS) structures containing the ML films are characterized with high frequency capacitance-voltage (C-V), conductance-voltage (G-V) and photo-current measurements. These characterizations show that the annealed ML films have high defects centers than the as-deposited ML films. A shift in the C-V plot and a peak shift in the G-V plot for the annealed ML film are due to the charge storage in the defects centers and the quantized states of Si-QDs. The defect centers introduced low photo-response for the annealed ML film (Si-QD structure) than the as-deposited ML films.