Current stress instability analysis of amorphous InGaZnO thin film transistors

1. Introduction Recent researches from the demands of large size liquid crystal flat panel displays, low cost process and higher performance arouse great interest on amorphous oxide semiconductor based thin-film transistors (TFTs) as an alternative of a-Si TFTs. To achieve device reliability and stability under various current/voltage bias, temperature, and light injections, various researches on amorphous InGaZnO (a-IGZO) channel material have been reported [1,2,3]. It is reported that the deterioration of a-IGZO channel is mainly induced by conditions of trap state, such as oxygen vacancy and it can be enhanced by passivation or annealing process [3]. However, researches on current injection to the TFT channel need to be investigated to achieve optimized performance characteristics at current stress condition. In this study, we investigated channel degradation characteristics applying current stress to a-IGZO channel with different bulk thickness.