Patent ID: 9633844
Date: 2017-04-25
CPC Classifications: H01L

Claim:
1. A method for forming a low temperature polysilicon thin film comprising: depositing a buffer layer and an amorphous silicon layer sequentially on a substrate; heating the amorphous silicon layer, and then performing an excimer laser annealing process on the amorphous silicon layer to form a polysilicon layer; oxidizing partially the polysilicon layer so as to form an oxidation portion at an upper portion of the polysilicon layer; and removing the oxidation portion of the polysilicon layer to form a polysilicon thin film; wherein oxidizing partially of the polysilicon layer comprises oxidizing partially the polysilicon layer with nitrous oxide plasma, and oxidizing is performed under conditions comprising a temperature higher than 400° C., a flow rate of reactive gas from 1000 to 2000 sccm, a radio-frequency power of 700 W, a pressure in a deposition chamber from 1500 to 3000 mtorr, and an oxidation duration from 2 to 7 minutes.