Unusual Threshold Voltage Shift Caused by Self-Heating-Induced Charge Trapping Effect

Abstract

This article investigates the threshold voltage (V(t)) shift induced by a self-heating effect for n-channel low temperature poly-Si thin film transistors (TFTs) and finds that there is a shift of more than 3 V in the negative direction after a self-heating operation of 100 ms. The negative V(t) shift can be attributed to the charge-trapping effect caused by the holes generated by trap-assisted band-to-band thermionic field emission and trapped in the grain boundary of the poly-Si film substrate. We used lateral body contact structure to verify that this unusual V(t) shift is related to the holes trapped in the substrate. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3290686] All rights reserved.