High Current Density in m c-Si PECVD Diodes for Low Temperature Applications

The development of microcrystalline diodes grown at low temperature by PECVD techniques is reported. Current densities near 200 A/cm 2 at + 2 V, and rectification ratios on the order of 10 5 at +/- 1V and 10 7 at +/- 2V were obtained. The reverse currents were in the nano-ampere range. Correlations between deposition conditions and film quality are presented. The effects of mesa formation and subsequent treatments designed to reduce process damage are discussed: annealing conditions yield an increase in forward current, and a decrease in reverse current. Fabrication conditions are compatible with applications requiring low temperature processes (e. g., multi-layer structures, molecular layers, or plastic substrates and coatings).