Coplanar Poly-Si TFT on Flexible Metal Foil Using Spin-On Glass as Gate Insulator and Planarization

Abstract

Methylsiloxane-based spin-on-glass (M-SOG) has been applied to a polycrystalline silicon thin-film transistor (TFT) on a -thick flexible metal foil as a gate dielectric and planarization layer as well. Triple spin coatings and curing of M-SOG layers reduce the surface roughness of the metal foil from 800 to . The p-channel metal-induced crystallization of using a cap TFT using M-SOG on a metal foil exhibited a field-effect mobility of , a threshold voltage of , and a minimum off-state current of at . The poly-Si TFT was found to be stable against a negative gate-bias stress. Therefore, the low-cost, low-temperature polycrystalline silicon TFT can be applied to make flexible displays.