High performance poly-si thin film transistors (TFTs) fabricated by xecl excimer laser annealing without post-hydrogenation

Abstract

Plasma hydrogenation has long been used to passivate grain boundary states in poly-Si TFTs . I Device performance improves significantly with the incorporation of hydrogen. However, long term stability has been shown to suffer.2 We report a technique for low temperature TFT fabrication suitable for display driver circuit applications on glass, providing excellent device characteristics without the need for intentional hydrogenation. A pulsed XeCl excimer laser was used to recrystallize pre-patterned a-silicon. High mobility, low leakage currents, and sharp subthreshold slopes have been achieved. The enhanced device performance over previous reported results is attributed to pre-patterning before laser annealing leading to enhanced lateral grain growth.