Stable microcrystalline silicon thin-film transistors produced by the layer-by-layer technique

Microcrystalline silicon thin films prepared by the layer-by-layer techniqu e in a standard radio-frequency glow discharge reactor were used as the act ive layer of top-gate thin-film transistors (TFTs). Crystalline fractions a bove 90% were achieved for silicon films as thin as 40 nm and resulted in T FTs with smaller threshold voltages than amorphous silicon TFTs, but simila r field effect mobilities of around 0.6 cm(2)/V s. The most striking proper ty of these microcrystalline silicon transistors was their high electrical stability when submitted to bias-stress tests. We suggest that the excellen t stability of these TFTs, prepared in a conventional plasma reactor, is du e to the stability of the mu c-Si:H films. These TFTs can be used in applic ations that require high stability for which a-Si:H TFTs cannot be used, su ch as multiplexed row and column drivers in flat-panel display applications , and active matrix addressing of polymer light-emitting diodes. (C) 1999 A merican Institute of Physics. [S0021-8979(99)05324-4].