Abstract: An amorphous silicon layer and at least a heat-retaining layer are formed on a substrate in turn. Wherein, the heat-retaining layer is controlled to have an anti-reflective thickness for reducing the threshold laser energy to effect the melting of the amorphous silicon layer. Then, a laser irradiation process is performed to transform the amorphous silicon layer into a polycrystalline silicon layer. During the laser irratiation process, a portion of the laser energy transmits the heat-retaining layer to effect the melting of the amorphous silicon layer, and another portion of the laser energy is absorbed by the heat-retaining layer.

Abstract: A method for planarizing polysilicon comprises providing a substrate, forming a dielectric layer on the substrate, forming an amorphous silicon film on the dielectric layer, etching the amorphous silicon film to remove native oxide formed on a surface of the amorphous silicon film, exposing the surface of the amorphous silicon film to a first radiation source to polycrystallize the amorphous silicon film into a polysilicon film, etching the polysilicon film to remove weak bonded silicon formed on a surface of the polysilicon film, and exposing the surface of the polysilicon film to a second radiation source to reflow the polysilicon film.

Abstract: An amorphous silicon layer is formed on a substrate, and then a protective layer and a reflective layer are formed in turn to form a film stack on portions of the amorphous silicon layer. The reflective layer is a metal material with reflectivity of laser, and the protective layer is able to prevent metal diffusion. When an excimer laser heats the amorphous silicon layer to crystallize the amorphous silicon, nucleation sites are formed in the amorphous silicon layer under the film stack of the protective layer and the reflective layer. Next, laterally expanding crystallization occurs in the amorphous silicon layer to form poly-silicon having crystal grains with size of micrometers and high grain order.

Abstract: An amorphous silicon layer is formed on a substrate, and then a protective layer and a reflective layer are formed in turn to form a film stack on portions of the amorphous silicon layer. The reflective layer is a metal material with reflectivity of laser, and the protective layer is able to prevent metal diffusion. When an excimer laser heats the amorphous silicon layer to crystallize the amorphous silicon, nucleation sites are formed in the amorphous silicon layer under the film stack of the protective layer and the reflective layer. Next, laterally expanding crystallization occurs in the amorphous silicon layer to form poly-silicon having crystal grains with size of micrometers and high grain order.

Abstract: A heat sink layer is formed on portions of a substrate, and then an amorphous silicon layer is formed thereon. The heat coefficient of the heat sink layer is greater than that of the substrate. When an excimer laser heats the amorphous silicon layer to crystallize the amorphous silicon, nucleation sites are formed in the amorphous silicon layer on the heat sink layer. Next, laterally expanding crystallization occurs in the amorphous silicon layer on the substrate to form polysilicon having a crystal size of a micrometer.

Abstract: The present invention relates to a method for planarizing polysilicon. The method includes providing a substrate with polysilicon on the surface, etching the surface of the polysilicon to initially reduce surface roughness, and laser annealing the polysilicon to partially melt the polysilicon to planarize the surface thereof.