Semiconductor film, semiconductor device and method of their production

• US 20020182828A1
• Filed: 05/29/2002
• Published: 12/05/2002
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yonezawa, Masato, Suzuki, Noriyoshi, Ohnuma, Hideto, Asami, Taketomi, Ichijo, Mitsuhiro
• Granted Patent: US 6,743,700 B2
• Time in Patent Office: Days
• US Class Current: 438/485
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C30B 1/023 from solids with amorphous structure
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02491 Conductive materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/3221 of silicon bodies, e.g. for gettering
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78636 with supplementary region or layer for improving the flatness of the device

Abstract

A semiconductor film having a crystalline structure is formed by using a metal element that assists the crystallization of the semiconductor film, and the metal element remaining in the film is effectively removed to decrease the dispersion among the elements. The semiconductor film or, typically, an amorphous silicon film having an amorphous structure is obtained based on the plasma CVD method as a step of forming a gettering site, by using a monosilane, a rare gas element and hydrogen as starting gases, the film containing the rare gas element at a high concentration or, concretely, at a concentration of 1×10²⁰/cm³ to 1×10²¹/cm³ and containing fluorine at a concentration of 1×10¹⁵/cm³ to 1×10¹⁷/cm³.

Claims

1. A method of manufacturing an amorphous semiconductor film, comprising:

introducing a starting gas including silane, a rare gas and hydrogen into a film-forming chamber;

generating a plasma of said starting gas; and

forming an amorphous semiconductor film comprising a rare gas element at a concentration of 1×

10¹⁸/cm³ to 1×

10²²cm³ using said plasma.

2. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein in generating the plasma, the pressure in the film-forming chamber is from 2.666 Pa to 133.3 Pa.

3. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the flow rate of hydrogen to the rare gas is controlled to be from 0.2 to 5.

4. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the RF power density for generating the plasma is from 0.0017 W/cm² to 1 W/cm².

5. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the rare gas element is one or more kinds selected from He, Ne, Ar, Kr and Xe.

6. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the silane is monosilane.

7. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 0.1:

99.9 to 1;

9.

8. A method of manufacturing an amorphous semiconductor film according to claim 1, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 1:

99 to 5;

95.

9. An amorphous semiconductor film comprising silicon wherein said amorphous semiconductor film contains a rare gas element at a concentration of from 1×

10¹⁸/cm³ to 1×

10²⁰/cm³; and

fluorine at a concentration of from 1×

10¹⁵/cm³ to 1×

10¹⁷/cm³.

10. A method of manufacturing a semiconductor device comprising:

forming a first amorphous semiconductor film on an insulating surface;

adding a metal element to the first amorphous semiconductor film;

forming a second crystalline semiconductor film by crystallizing the first amorphous semiconductor film;

forming a barrier layer on a surface of the second crystalline semiconductor film;

forming a third semiconductor film comprising a rare gas element on the barrier layer by a plasma CVD method;

removing or decreasing the metal element in the second crystalline semiconductor film by gettering the metal element into the third semiconductor film; and

removing the third semiconductor film,

wherein the third semiconductor film is formed by a plasma CVD method that generates plasma by introducing silane, a rare gas and hydrogen as starting gases into a film-forming chamber.

11. A method of manufacturing a semiconductor device according to claim 10, wherein the metal element is one or more kinds selected from Fe, Ni, Co, Ru, Rh, Pd, Os, Ir, Pt, Cu and Au.

13. A method of manufacturing a semiconductor device according to claim 12, wherein in generating the plasma, the pressure in the film-forming chamber is from 2.666 Pa to 133.3 Pa.

14. A method of manufacturing a semiconductor device according to claim 12, wherein the flow rate of hydrogen to the rare gas is controlled to be from 0.2 to 5.

15. A method of manufacturing a semiconductor device according to claim 12, wherein the RF power density for generating the plasma is from 0.0017 W/cm² to 1 W/cm².

16. A method of manufacturing a semiconductor device according to claim 12, wherein the rare gas element is one or more kinds selected from He, Ne, Ar, Kr and Xe.

17. A method of manufacturing a semiconductor device according to claim 12, wherein the silane is monosilane.

18. A method of manufacturing a semiconductor device according to claim 12, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 0.1:

99.9 to 1;

9.

19. A method of manufacturing a semiconductor device according to claim 12, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 1:

99 to 5;

95.

12. A method of manufacturing a semiconductor device, comprising:

forming a gate electrode over a substrate;

forming a gate insulating film on the gate electrode;

introducing a starting gas including silane, a rare gas and hydrogen;

generating a plasma of the starting gas;

forming an amorphous semiconductor film comprising a rare gas element at a concentration of 1×

10¹⁸/cm³ to 1×

10²²cm³ ; and

patterning the amorphous semiconductor film.

20. A method of manufacturing a semiconductor device comprising:

forming a first semiconductor film on an insulating surface;

forming a barrier layer on a surface of the first semiconductor film;

forming a second semiconductor film comprising a rare gas element on the barrier layer by a plasma CVD method;

removing or decreasing a metal element contained in the first semiconductor film by gettering the metal element into the second semiconductor film; and

removing the second semiconductor film,

wherein the second semiconductor film is formed by plasma CVD using silane, a rare gas and hydrogen as starting gases.

21. A method of manufacturing a semiconductor device according to claim 20, wherein the silane is monosilane.

22. A method of manufacturing a semiconductor device according to claim 20, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 0.1:

99.9 to 1;

9.

23. A method of manufacturing a semiconductor device according to claim 20, wherein the silane is monosilane and the flow rate of the monosilane to the rare gas introduced into the film-forming chamber is controlled to be from 1:

99 to 5;

95.