Thin Film Transistor Gate Insulation Segmentation for Polysilicon Crystallization

The gate insulating layer is segmented into a first insulating layer and a second insulating layer. The first insulating layer is formed on the substrate and gate, while the second insulating layer is formed on the first insulating layer. This segmentation allows the gate insulating layer to be formed in multiple steps, enabling better control over the height difference and providing a more favorable surface for semiconductor layer crystallization while maintaining the simplified bottom gate structure.

The gate insulating layer is formed preliminarily in a two-layer structure before forming the semiconductor layer. The first insulating layer is formed on the substrate and gate, and the second insulating layer is formed on the first insulating layer. This preliminary formation of a multi-layer gate insulating structure creates a more favorable surface for subsequent semiconductor layer deposition and crystallization, ensuring better transistor performance while maintaining ease of manufacture.

The semiconductor layer undergoes a phase change from amorphous silicon to polysilicon through laser annealing treatment. This parameter change in the material structure transforms the semiconductor properties, reducing contact resistance and power consumption while maintaining the manufacturing simplicity of using amorphous silicon as the starting material. The laser annealing process converts the amorphous silicon into a more conductive polysilicon form.