We have investigated temperature dependence on the hysteresis phenomenon of SLS poly-Si TFT on a glass substrate, extremely at low temperature (213K). The p-type sequential lataral solidification (SLS) polycrystalline Silicon (poly-Si) TFT was fabricated on glass substrate. As the temperature was reduced, it was observed that hysteresis phenomenon was increased, whereas the hysteresis was suppressed at high temperature. This could be explained by a difference of initially electron and hole trapped charges into gate insulator is much larger in low temperature than in high temperature. And we have verified that drain current was changed with a different previous gate starting voltage even at same bias condition by experimental results due to the hysteresis phenomenon of SLS poly-Si TFT. Hysteresis of SLS poly-Si TFT should be improved for a pixel element of high quality AMOLED display.

We have studied the improvement of the quality of undoped a-Si:H deposited by remote-plasma chemical vapour deposition. The effects of reactant gas concentration, rf power, substrate bias voltage on the electrical and optical properties have been investigated. Some hydrogen dilution of si lane improves the photoeletric property and a high rf power gives rise to the defect creation due to the ion bombardment on the growing surface. The positive substrate bias improves the quality of undoped a-Si:H.