Abstract
We have studied the effect of Ci incorporation on the performance of amorphous silicon thin film transistors (a-Si : H ( : Cl) TFTs). The off-state leakage currents of a-Si : H ( : Cl) TFTs under light illuminations are much lower than those of a-Si : H TFT, caused by the fact that the photoconductivity of a-Si : H ( : Cl) are much lower than those of conventional a-Si : H. The a-Si : H ( : Cl) films deposited between [SiH_2Cl_2]/[SiH_4]=0.04 and [SiH_2Cl_2]/[SiH_4]=0.12 show a p-type conduction, leading to much lower photoconductivity. The TFT using a-Si : H ( : Cl) deposited with [SiH_2Cl_2]/[SiH_4]=0.04 exhibited a field effect mobility of 0.41 cm^2/Vs and a threshold voltage of 5.56 V, but the off-state leakage current under light illumination is 2 orders of magnitude smaller than that of conventional a-Si : H TFT.
