Inhibiting the Kink Effect and Hot-Carrier Stress Degradation Using Dual-Gate Low-Temperature Poly-Si TFTs

Abstract

This study examines the appearance of a kink effect phenomenon in the I D -V D electrical characteristics of low-temperature polycrystalline Si thin-film transistors (LTPS TFTs) after high-current-induced hot-carrier stress (HCS). During HCS, electron-hole pairs were generated in the channel near the drain terminal owing to impact ionization. Next, the electrons were repelled towar the source by the drain electric field, thereby inducing the floating body effect, which lowered the source barrier. In addition, a dualgate-structured LTPS was found to inhibit the electrical degradation caused by HCS. The COMSOL simulation indicated that in the dual-gate structure, holes at the upper and lower margins of the channel were inverted and inhibited the degradation caused by the floating body effect. Therefore, the use of dual-gate LTPS TFTs could facilitate high-current gate-on-array circuit applications in display panels.