Method of fabricating polysilicon thin film and thin film transistor using polysilicon fabricated by the same method
View Patent ↗A method of fabricating a polysilicon thin film produces a polysilicon thin film which is used to make a thin film transistor. The method includes depositing a silicon film containing amorphous silicon on a substrate, and performing thermal treatment on the silicon film at a predetermined temperature in an H 2 O atmosphere. Accordingly, the crystallization temperature and thermal treatment time are decreased when the amorphous silicon is crystallized by a solid phase crystallization method, and this prevents the substrate from being bent due to application of a thermal treatment process for a long time and at a high temperature. As a result of the invention, a polysilicon thin film having superior crystallization properties is obtained. Use of the polysilicon thin film in a thin film transistor results in the reduction of defects in the thin film resistor.
1. A method of fabricating a polysilicon thin film, comprising:
depositing a silicon film containing amorphous silicon on a substrate; and
crystallizing the silicon film via solid phase crystallization by performing thermal treatment on the silicon film in an atmosphere that includes H 2 O at a predetermined temperature;
wherein a pressure of the H 2 O is at least 10,000 Pa and the thermal treatment has a duration of 10 minutes or less.
2. The method of claim 1 , wherein the predetermined temperature is in a range of 550° C. to 750° C.
3. The method of claim 2 , wherein the predetermined temperature is in a range of 600° C. to 700° C.
4. The method of claim 1 , wherein the partial pressure of the H 2 O is in a range of 10,000 Pa to 2 MPa.
5. The method of claim 1 , wherein a thickness of the silicon film is no greater than 2000 Å.
6. The method of claim 5 , wherein the thickness of the silicon film is in a range of 300 Å to 1,000 Å.
7. A method of fabricating a polysilicon thin film, comprising:
depositing a silicon film containing amorphous silicon on a substrate; and
crystallizing the silicon film by solid phase crystallization by performing thermal treatment on the silicon film in an atmosphere that includes H 2 O at a predetermined temperature, a pressure of the H 2 O in said atmosphere being at least 100,000 Pa, the thermal treatment having a duration of 10 minutes or less.
8. A method of fabricating a polysilicon thin film, comprising:
depositing a silicon film containing amorphous silicon on a substrate; and
producing said polysilicon thin film by solid phase crystallization by performing a thermal treatment on the silicon film in an atmosphere that includes H 2 O at a predetermined temperature, a pressure of the H 2 O in said atmosphere being at least 10,000 Pa, said method being absent a melting of the silicon film, the thermal treatment having a duration of 10 minutes or less.
9. The method of claim 1 , wherein the silicon film is deposited by any one of a low pressure chemical vapor deposition (LPCVD) method and a plasma enhanced chemical vapor deposition (PECVD) method.
10. A method of fabricating a polysilicon thin film, comprising:
depositing a silicon film containing amorphous silicon on a substrate; and
crystallizing the silicon film via solid phase crystallization by performing a thermal treatment on the silicon film in an H 2 O atmosphere at a predetermined temperature, the thermal treatment on the silicon film is performed in the H 2 O atmosphere at a pressure of at least 10,000 Pa, the thermal treatment having a duration of 10 minutes or less.
11. The method of claim 8 , wherein the pressure of the H 2 O in said atmosphere is in a range of 100,000 Pa to 2 MPa.
12. The method of claim 10 , further comprising performing thermal treatment on the silicon film by an excimer laser annealing (ELA) method once more after performing the thermal treatment on the silicon film in the H 2 O atmosphere at the predetermined temperature.
13. The method of claim 1 , wherein the pressure of the H 2 O is in a range of 100,000 Pa to 2 Mpa.
14. The method of claim 10 , wherein the thermal treatment on the silicon film is performed in the H 2 O atmosphere at a pressure of at least 100,000 Pa.