Low-temperature plasma-processed microcrystalline silicon thin films for large-area electronics

Microcrystalline silicon thin films produced by three methods based on the standard radio-frequency glow discharge technique were used as the active layer of top-gate thin film transistors. Crystalline fractions above 96% were achieved even for films as thin as 30 nm and resulted in thin film transistors with smaller threshold voltages than a-Si:H thin film transistors and field effect mobilities up to 1 cm²/V.s. The most remarkable property of these transistors was their high electrical stability when submitted to bias stress tests. Our results indicate that the excellent stability is due to the high crystalline fraction, achieved at temperatures as low as 150°C.