Total-Dose Effect of X-ray Irradiation on Low-Temperature Polycrystalline Silicon Thin-Film Transistors

Abstract

In this paper, the total-dose effect of X-ray irradiation on low-temperature polycrystalline-silicon (LTPS) thin film transistors (TFTs) is studied. Experiments under different conditions, including fixed intensity, fixed time, fixed total dose, short shot with different frequencies and high/low intensity for short/long time were performed and analyzed. With an increase of the irradiation dose, the threshold voltage (Vth) shifts negatively, the subthreshold swing (S.S.) degrades and the field effect mobility decreases owing to positive trapped charges and interface traps. All magnitude of negative shifts of (Vth), (S. S.) and field effect mobility for LTPS TFTs are well correlated to the total accumulated dose. The results are consistent with (Vth) shift due to trapped holes and the interface traps for mobility.