Investigation on stress induced hump phenomenon in IGZO thin film transistors under negative bias stress and illumination

The cause of the stress induced hump occurrence in IGZO thin film transistor has been investigated through experiment and device simulation. The hole accumulation and trapping into the edge region under negative bias stress and illumination have been found to be the cause of the hump occurrence. The effects of the quantity of the hole trapped charges and the edge region length on the hump occurrence have been discussed. From the device simulation, the optimized device design parameters, such as the IGZO film thickness and the edge length, have been discussed to reduce the hump occurrence under negative bias stress and illumination. (C) 2015 Elsevier Ltd. All rights reserved.