METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20110237025A1
• Filed: 03/25/2011
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Granted Patent: US 8,551,810 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• CPC Class Codes: H01L 21/47635 After-treatment of these layers
• CPC Class Codes: H01L 21/477 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/38 - H01L21/449 and H01L21/461 - H01L21/475 take precedence
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• 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

In a transistor including an oxide semiconductor film, a metal oxide film for preventing electrification which is in contact with the oxide semiconductor film and covers a source electrode and a drain electrode is formed. Then, oxygen is introduced (added) to the oxide semiconductor film through the metal oxide film and heat treatment is performed. Through these steps of oxygen introduction and heat treatment, impurities such as hydrogen, moisture, a hydroxyl group, or hydride are intentionally removed from the oxide semiconductor film, so that the oxide semiconductor film is highly purified. Further, by providing the metal oxide film, generation of a parasitic channel on a back channel side of the oxide semiconductor film can be prevented in the transistor.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor film overlapping with the gate electrode with the gate insulating film interposed therebetween;

forming a source electrode and a drain electrode over the oxide semiconductor film;

forming a metal oxide film over the source electrode and the drain electrode, the metal oxide film being in contact with the oxide semiconductor film;

introducing oxygen to at least one of the oxide semiconductor film, the metal oxide film, and an interface between the oxide semiconductor film and the metal oxide film;

forming an insulating film over the metal oxide film after the step of introducing oxygen; and

performing heat treatment after forming the insulating film.

2. The method for manufacturing a semiconductor device, according to claim 1, wherein the metal oxide film comprises gallium oxide.

3. The method for manufacturing a semiconductor device, according to claim 1, wherein the metal oxide film is a gallium oxide film containing 0.01 at. % to 5 at. % of indium or zinc.

4. The method for manufacturing a semiconductor device, according to claim 1, wherein the heat treatment is performed at temperature of 450°

C. to 600°

C.

5. The method for manufacturing a semiconductor device, according to claim 1, wherein the oxide semiconductor film comprises indium and gallium.

6. The method for manufacturing a semiconductor device, according to claim 1, wherein the step of introducing oxygen is performed by accelerating oxygen ion.

7. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor film overlapping with the gate electrode with the gate insulating film interposed therebetween;

forming a source electrode and a drain electrode over the oxide semiconductor film;

forming a metal oxide film over the source electrode and the drain electrode, the metal oxide film being in contact with the oxide semiconductor film;

forming an insulating film over the metal oxide film;

introducing oxygen to at least one of the oxide semiconductor film, the metal oxide film, and an interface between the oxide semiconductor film and the metal oxide film through the insulating film; and

performing heat treatment after the step of introducing oxygen.

8. The method for manufacturing a semiconductor device, according to claim 7, wherein the metal oxide film comprises gallium oxide.

9. The method for manufacturing a semiconductor device, according to claim 7, wherein the metal oxide film is a gallium oxide film containing 0.01 at. % to 5 at. % of indium or zinc.

10. The method for manufacturing a semiconductor device, according to claim 7, wherein the heat treatment is performed at temperature of 450°

C. to 600°

C.

11. The method for manufacturing a semiconductor device, according to claim 7, wherein the oxide semiconductor film comprises indium and gallium.

12. The method for manufacturing a semiconductor device, according to claim 7, wherein the step of introducing oxygen is performed by accelerating oxygen ion.

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

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor film overlapping with the gate electrode with the gate insulating film interposed therebetween;

performing first heat treatment on the oxide semiconductor film, the first heat treatment including heating in an inert atmosphere and cooling in an oxygen atmosphere;

forming a source electrode and a drain electrode over the oxide semiconductor film;

forming a metal oxide film over the source electrode and the drain electrode, the metal oxide film being in contact with the oxide semiconductor film;

introducing oxygen to at least one of the oxide semiconductor film, the metal oxide film, and an interface between the oxide semiconductor film and the metal oxide film;

forming an insulating film over the metal oxide film after the step of introducing oxygen; and

performing second heat treatment after forming the insulating film.

14. The method for manufacturing a semiconductor device, according to claim 13, wherein the metal oxide film comprises gallium oxide.

15. The method for manufacturing a semiconductor device, according to claim 13, wherein the metal oxide film is a gallium oxide film containing 0.01 at. % to 5 at. % of indium or zinc.

16. The method for manufacturing a semiconductor device, according to claim 13, wherein the first heat treatment is performed at temperature of 450°

C. to 600°

C.

17. The method for manufacturing a semiconductor device, according to claim 13, wherein the oxide semiconductor film comprises indium and gallium.

18. The method for manufacturing a semiconductor device, according to claim 13, wherein the step of introducing oxygen is performed by accelerating oxygen ion.

19. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor film overlapping with the gate electrode with the gate insulating film interposed therebetween;

performing first heat treatment on the oxide semiconductor film, the first heat treatment including heating in an inert atmosphere and cooling in an oxygen atmosphere;

forming a source electrode and a drain electrode over the oxide semiconductor film;

forming a metal oxide film over the source electrode and the drain electrode, the metal oxide film being in contact with the oxide semiconductor film;

forming an insulating film over the metal oxide film;

introducing oxygen to at least one of the oxide semiconductor film, the metal oxide film, and an interface between the oxide semiconductor film and the metal oxide film through the insulating film; and

performing second heat treatment after the step of introducing oxygen.

20. The method for manufacturing a semiconductor device, according to claim 19, wherein the metal oxide film comprises gallium oxide.

21. The method for manufacturing a semiconductor device, according to claim 19, wherein the metal oxide film is a gallium oxide film containing 0.01 at. % to 5 at. % of indium or zinc.

22. The method for manufacturing a semiconductor device, according to claim 19, wherein the first heat treatment is performed at temperature of 450°

C. to 600°

C.

23. The method for manufacturing a semiconductor device, according to claim 19, wherein the oxide semiconductor film comprises indium and gallium.

24. The method for manufacturing a semiconductor device, according to claim 19, wherein the step of introducing oxygen is performed by accelerating oxygen ion.