Abstract: A self-aligned polysilicon thin film transistor, and a method for manufacturing it, is described. An insulating substrate is provided. A gate electrode is formed on the insulating substrate. A protective light-absorbing layer is formed over the gate electrode and over the insulating substrate. The protective light-absorbing layer is patterned. A gate dielectric layer is formed over the protective light-absorbing layer and over the insulating substrate. A layer of amorphous silicon is formed over the gate dielectric layer. A photoresist mask is formed over the layer of amorphous silicon, aligned with the protective light-absorbing layer. The amorphous silicon layer is implanted with a conductivity-imparting dopant in source/drain regions not protected by the photoresist mask. The photoresist mask is removed. The amorphous silicon layer is laser-annealed, whereby doped polysilicon is formed in the source/drain regions, and undoped polysilicon is formed in areas between the source/drain regions.

Abstract: A self-aligned polysilicon thin film transistor, and a method for manufacturing it, is descrbed. An insulating substrate is provided. A gate electrode is formed on the insulating substrate. A protective light-absorbing layer is formed over the gate electrode and over the insulating substrate. The protective light-absorbing layer is patterned. A gate dielectric layer is formed over the protective light-absorbing layer and over the insulating substrate. A layer of amorphous silicon is formed over the gate dielectric layer. A photoresist mask is formed over the layer of amorphous silicon, aligned with the protective light-absorbing layer. The amorphous silicon layer is implanted with a conductivity-imparting dopant in source/drain regions not protected by the photoresist mask. The photoresist mask is removed. The amorphous silicon layer is laser-annealed, whereby doped polysilicon is formed in the source/drain regions, and undoped polysilicon is formed in areas between the source/drain regions.