CHARACTERISTICS OF POLYSILICON TFTs, HYDROGENATED BY ION IMPLANTATION P-CHANNEL

Self-aligned polycrystalline silicon thin film transistors (PS TFTs) with different phosphorus channel doping have been investigated by the conduction method. The polysilicon gate was heavily doped by ion implantation of phosphorus. The source and drain electrodes were heavily doped by ion implantation of boron. A gate oxide 45 nm thick was grown in dry oxygen. On a parallel series of wafers, the grain boundary and gate oxide interface states were passivated by ion implantation of hydrogen through the polysilicon gate. Fitting the experimental data for the threshold voltages and hole mobilities with the theory reveal that hydrogenation by ion implantation improves the performance of the TFTs. The results confirm that such hydrogenation is a promising technology for the improvement of the performance of PS TFTs.