SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20090152550A1
• Filed: 12/15/2008
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ohnuma, Hideto, Hirose, Takashi
• Granted Patent: US 7,910,929 B2
• Time in Patent Office: Days
• US Class Current: 257/57
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/32055 Deposition of semiconductive layers, e.g. poly - or amorphous silicon layers
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

An object is to provide a semiconductor device including a microcrystalline semiconductor film with favorable quality and a method for manufacturing the semiconductor device. In a thin film transistor formed using a microcrystalline semiconductor film, yttria-stabilized zirconia having a fluorite structure is formed in the uppermost layer of a gate insulating film in order to improve quality of a microcrystalline semiconductor film to be formed in the initial stage of deposition. The microcrystalline semiconductor film is deposited on the yttria-stabilized zirconia, so that the microcrystalline semiconductor film around an interface with a base particularly has favorable crystallinity while by crystallinity of the base.

Claims

1. A semiconductor device comprising:

a substrate;

a gate electrode over the substrate;

a gate insulating film including an yttria-stabilized zirconia film over the gate electrode; and

a semiconductor film over the gate insulating film,

wherein the semiconductor film is in contact with the yttria-stabilized zirconia film.

2. The semiconductor device according to claim 1, wherein the gate insulating film includes one or a plurality of films selected from the group consisting of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a silicon nitride oxide film.

3. The semiconductor device according to claim 1, wherein the semiconductor film is a microcrystalline semiconductor film.

4. The semiconductor device according to claim 3, wherein the microcrystalline semiconductor film is a microcrystalline silicon film.

5. The semiconductor device according to claim 3, wherein the microcrystalline semiconductor film contains germanium.

6. The semiconductor device according to claim 1, further comprising an amorphous semiconductor film,

wherein the amorphous semiconductor film is located over the semiconductor film and in contact with the semiconductor film, and

wherein the amorphous semiconductor film has a depressed portion on a top surface.

7. A semiconductor device comprising:

a substrate;

a gate electrode over the substrate;

a gate insulating film including an yttria-stabilized zirconia film over the gate electrode;

a first semiconductor film over the gate insulating film;

a second semiconductor film over the first semiconductor film, the second semiconductor film having a depressed portion on a top surface;

a third semiconductor film over the second semiconductor film without the depressed portion of the second semiconductor film; and

a conductive film over the third semiconductor film,

wherein the first semiconductor film is in contact with the yttria-stabilized zirconia film, and

wherein edge portions of the third semiconductor film are located at outside of edge portions of the conductive film.

8. The semiconductor device according to claim 7, wherein the gate insulating film includes one or a plurality of films selected from the group consisting of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a silicon nitride oxide film.

9. The semiconductor device according to claim 7, wherein the first semiconductor film is a microcrystalline semiconductor film.

10. The semiconductor device according to claim 9, wherein the microcrystalline semiconductor film is a microcrystalline silicon film.

11. The semiconductor device according to claim 9, wherein the microcrystalline semiconductor film contains germanium.

12. The semiconductor device according to claim 7,

wherein edge portions of the second semiconductor film are located at outside of edge portions of the third semiconductor film.

13. A method for manufacturing a semiconductor device, comprising:

forming a first wiring over a substrate;

forming an insulating film containing an yttria-stabilized zirconia film over the first wiring;

forming a semiconductor film so as to be in contact with the yttria-stabilized zirconia film;

forming an island-like semiconductor film by selective etching of the semiconductor film; and

forming a second wiring over the island-like semiconductor film.

14. The method for manufacturing a semiconductor device, according to claim 13, wherein a surface of the insulating film containing yttria-stabilized zirconia is subjected to plasma treatment using H₂, O₂, Ar, or N₂ or a combination of any of the above.

15. The method for manufacturing a semiconductor device, according to claim 14, wherein the plasma treatment is reverse sputtering treatment.

16. The method for manufacturing a semiconductor device, according to claim 13, wherein the insulating film includes one or a plurality of films selected from the group consisting of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a silicon nitride oxide film.

17. The method for manufacturing a semiconductor device, according to claim 13, further comprising the step of, forming an amorphous semiconductor film over the semiconductor film.

18. The method for manufacturing a semiconductor device, according to claim 13,

wherein the semiconductor film is formed under a first deposition condition and a second deposition condition,

wherein a deposition rate of the first deposition condition is low but a high-quality film can be formed, and

wherein a deposition rate of the second deposition condition is higher than that of the first deposition condition.

19. The method for manufacturing a semiconductor device, according to claim 13, wherein the yttria-stabilized zirconia film is formed by a sputtering method.