Method of hydrogenating a poly-silicon layer
A method of hydrogenating a poly-silicon layer is disclosed, which is used to improve characteristics of a thin film transistor (TFT) having a poly-silicon thin film. In the method, the poly-silicon layer is first subject to a plasma pre-process and then a hydrogenating process is undertaken thereon where a hydrogen-containing silicon-based compound is deposited over the poly-silicon layer having being pre-processed by the plasma and thermal treated. As such, the hydrogen atoms in the hydrogen-containing silicon-based compound may diffuse into the poly-silicon layer and the hydrogen atoms at a surface of the poly-silicon layer may further diffuse into where need to be filled to promote the hydrogenation effect of the poly-silicon layer, i.e., the hydrogenation may be completed in a shorter time.
1. A method of hydrogenating a poly-silicon layer in a thin film transistor (TFT), comprising the steps of:
providing a substrate having a poly-silicon layer;
treating a surface of said poly-silicon layer with a hydrogen-containing plasma so as to introduce hydrogen into said poly-silicon layer;
depositing a hydrogen-containing silicon-based compound on said poly-silicon; and
conducting a thermal treating on said hydrogen-containing silicon-based compound.
2. The method according to claim 1 , wherein said hydrogen-containing gas is a hydrogen gas.
3. The method according to claim 1 , wherein said hydrogen-containing gas is an ammonia gas.
4. The method according to claim 1 , wherein said hydrogen-containing silicon-based compound is a hydrogen-containing silicon nitride (SiN x :H).
5. The method according to claim 1 , wherein said step of exciting said hydrogen-containing gas to produce a hydrogen-containing plasma is executed by a plasma exciter.
6. The method according to claim 1 , wherein said steps of treating said poly-silicon layer and depositing a hydrogen silicon-based compound over said surface of said poly-silicon layer are both executed in a same process chamber.
7. The method according to claim 1 , wherein said substrate is placed in a thin film deposition system.
8. The method according to claim 1 , wherein said thin film deposition system is a plasma-enhanced chemical vapor deposition (PECVD) system.
9. The method according to claim 8 , wherein said plasma-enhanced chemical vapor deposition system is a radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) system.
10. The method according to claim 8 , wherein said plasma-enhanced chemical vapor deposition system is an electron cyclotron resonance chemical vapor deposition (ECR-CVD) system.
11. The method according to claim 8 , wherein said plasma-enhanced chemical vapor deposition system is a remote plasma chemical vapor deposition system.
12. The method according to claim 8 , wherein said plasma-enhanced chemical vapor deposition system is a magnetic plasma chemical vapor deposition.
13. The method according to claim 1 , wherein said step of conducting a thermal treating is conducted before a formation of an gate insulating layer.