P‐6: Reliability of Low Temperature Poly‐Si Thin Film Transistor

Abstract The novel four‐terminal device structure of low temperature polysilicon LTPS thin film transistors TFTs has been proposed in this paper and utilized to investigate the degradation mechanism of LTPS TFTs. The degradation mechanism under DC stress could be explained by the substrate current. By the inspecting of substrate current, the DC and AC degradation phenomenon were discussed and applied to lifetime prediction of n‐channel TFTs. The experimental results showed that the AC stress mode was preferred to predict the lifetime of n‐channel TFTs. Instead, the DC stress mode was more suitable for reliability testing of p‐channel TFTs because the dominant degradation mechanism was self‐heating.