Method for fabricating polysilicon film
View Patent ↗A method of fabricating a polysilicon film includes: forming a seed layer on a surface of a substrate; forming a silicon layer over the surface of the seed layer; and performing a laser annealing process to transform the silicon layer into a polysilicon layer at a laser energy equal to or greater than that needed to cause complete melting of the silicon layer.
1. A method of fabricating a polysilicon film comprising:
forming a seed layer with a highly preferred orientation on a surface of a substrate, wherein the seed layer comprises cerium oxide (CeO 2 ), calcium fluoride (CaF 2 ), or zirconium oxide (ZrO 2 );
forming an amorphous silicon layer over the surface of the seed layer; and
performing a laser annealing process to transform the amorphous silicon layer into a polysilicon layer according to the highly preferred orientation of the seed layer and at a laser energy equal to or greater than that needed to cause complete melting of the amorphous silicon layer.
2. The method of claim 1 , wherein the substrate is a glass substrate.
3. The method of claim 1 further comprising forming a barrier layer between the seed layer and the substrate.
4. The method of claim 1 , wherein the formation of the seed layer is achieved by sputtering, atomic layer deposition (ALD), evaporation, or chemical vapor deposition (CVD).
5. The method of claim 1 , wherein the formation of the amorphous silicon layer is achieved by chemical vapor deposition.
6. The method of claim 1 , wherein the thickness of the seed layer is 500 to 5000 angstroms.
7. The method of claim 1 , wherein the seed layer comprises a crystal structure.
8. The method of claim 7 , wherein the seed layer is lattice-matched to the polysilicon layer.
9. The method of claim 7 , wherein the grain size of the seed layer is from 500 to 5000 angstroms.
10. The method of claim 1 , wherein the laser annealing process comprises excimer laser annealing process, or solid-state laser annealing process.
11. The method of claim 1 , wherein the laser annealing process is performed at an energy of 250 to 500 mJ/cm2.
12. The method of claim 1 , further comprising utilizing a plurality of laser pulses for performing the laser annealing process.
13. The method of claim 12 , further comprising utilizing 2 to 10 pulses for performing the laser annealing process.
14. A method of fabricating a thin film transistor, comprising:
forming a polysilicon layer on a substrate, the substrate comprising an active area, a source, and a drain active layer comprising area;
forming a gate insulating layer on the polysilicon layer;
forming a gate layer on the gate insulating layer,
wherein the polysilicon layer is formed by the following steps:
forming a seed layer with a highly preferred orientation on a surface of a substrate, wherein the seed layer comprises cerium oxide (CeO 2 ), calcium fluoride (CaF 2 ), or zirconium oxide (ZrO 2 );
forming an amorphous layer over the surface of the seed layer; and
performing a laser annealing process to transform the amorphous silicon layer into a polysilicon layer according to the highly preferred orientation of the seed layer and at a laser energy equal to or greater than that needed to cause complete melting of the amorphous silicon layer.
15. A method of fabricating a display panel, comprising:
forming a top substrate having a common electrode and a color filter disposed thereon;
forming a bottom substrate having a pixel electrode disposed thereon;
forming the thin film transistor on the bottom substrate according to the method as claimed in claim 14 ; and
forming a liquid crystal layer disposed between the top substrate and the bottom substrate.
16. A method of fabricating an electronic device, comprising:
forming the display panel according to the method as claimed in claim 15 ; and
forming an input unit coupled to the display panel and operative to provide input to the display panel such that the display panel displays images.