Investigation and active suppression of self-heating induced degradation in amorphous InGaZnO thin film transistors**Project supported by the National Key R&D Program of China (Grant No. 2016YFB0400100), the National Natural Science Foundation of China (Grant No. 91850112), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20161401), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, the Science

Abstract

Self-heating effect in amorphous InGaZnO thin-film transistors remains a critical issue that degrades device performance and stability, hindering their wider applications. In this work, pulsed current–voltage analysis has been applied to explore the physics origin of self-heating induced degradation, where Joule heat is shortly accumulated by drain current and dissipated in repeated time cycles as a function of gate bias. Enhanced positive threshold voltage shift is observed at reduced heat dissipation time, higher drain current, and increased gate width. A physical picture of Joule heating assisted charge trapping process has been proposed and then verified with pulsed negative gate bias stressing scheme, which could evidently counteract the self-heating effect through the electric-field assisted detrapping process. As a result, this pulsed gate bias scheme with negative quiescent voltage could be used as a possible way to actively suppress self-heating related device degradation.