Method for fabrication of polycrystallin silicon thin film transistors

Abstract

A method for fabricating polycrystalline silicon film transistors, which includes a polysilicon spacer capping onto a sidewall of an active layer in the thin film transistors by an isotropic dry etching of the silicon film. This method suppresses the shrinkage of the active layer during recrystallization by the laser. Large grains are formed in the channel after recrystallization utilizing a high-energy continuous wavelength laser or an excimer laser annealing the active layer. This process does not require an additional mask. Uniform arrangement of grain boundaries and large grain sizes promotes uniformity of performance of the device, which is important in the fields of low temperature polycrystalline silicon thin film transistors (LTPS-TFTs).