Method for manufacturing semiconductor device

• US 9,601,603 B2
• Filed: 03/16/2016
• Issued: 03/21/2017
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Miyairi, Hidekazu, Osada, Takeshi, Yamazaki, Shunpei
• Primary Examiner(s): YUSHIN, NIKOLAY K
• Application Number:
  US15/071,674
• Publication Number:
  US 20160197166A1
• Time in Patent Office: 370 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• 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 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 27/1259 Multistep manufacturing methods
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/42356 Disposition, e.g. buried gate electrode H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• 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 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78645 with multiple gate
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of higher manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.

Claims

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

forming a first conductive film that serves as a gate electrode of a transistor;

forming a first insulating film over the first conductive film;

forming an oxide semiconductor layer that comprises a channel formation region over the first insulating film;

forming a second insulating film over the oxide semiconductor layer; and

forming a transparent film over the second insulating film by a sputtering method,

wherein the first conductive film and the transparent film overlap each other with the oxide semiconductor layer therebetween, and

wherein the transparent film has a larger width than the oxide semiconductor layer in a channel width direction of the transistor.

2. The method according to claim 1, wherein the transparent film has a larger width than the oxide semiconductor layer in a channel length direction of the transistor.

3. The method according to claim 1, further comprising:

forming a source electrode and a drain electrode by patterning a second conductive film formed over the oxide semiconductor layer, whereby a top surface of a first region of the oxide semiconductor layer that is located between the source electrode and the drain electrode is partially etched to have a smaller thickness than a second region of the oxide semiconductor layer that is below the source electrode or the drain electrode.

4. The method according to claim 1, wherein the oxide semiconductor layer includes indium, zinc, and a metal different from indium and zinc.

5. The method according to claim 1, wherein the transparent film is a conductive film.

6. The method according to claim 1, further comprising:

performing a heat treatment on the oxide semiconductor layer.

7. The method according to claim 1, wherein the second insulating film is an oxide insulating film.

8. The method according to claim 1, wherein the second insulating film is in contact with the oxide semiconductor layer and the transparent film.

9. The method according to claim 1, wherein the transparent film includes indium.

10. The method according to claim 1, wherein the transparent film includes zinc.

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

forming a first conductive film that serves as a first gate electrode of a transistor;

forming a first insulating film over the first conductive film;

forming an oxide semiconductor layer that comprises a channel formation region over the first insulating film;

forming a source electrode and a drain electrode by patterning a second conductive film formed over the oxide semiconductor layer, whereby a top surface of a first region of the oxide semiconductor layer that is located between the source electrode and the drain electrode is etched to have a smaller thickness than a second region of the oxide semiconductor layer that is below the source electrode or the drain electrode;

forming a second insulating film over the oxide semiconductor layer, the source electrode, and the drain electrode; and

forming a transparent film over the second insulating film by a sputtering method.

12. The method according to claim 11, wherein the oxide semiconductor layer includes indium, zinc, and a metal different from indium and zinc.

13. The method according to claim 11, wherein the transparent film is a conductive film.

14. The method according to claim 11, further comprising:

performing a heat treatment on the oxide semiconductor layer.

15. The method according to claim 11, wherein the second insulating film is in contact with the oxide semiconductor layer and the transparent film.

16. The method according to claim 11, wherein the transparent film includes indium.

17. The method according to claim 11, wherein the transparent film includes zinc.

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

forming a first conductive film that serves as a first gate electrode of a transistor;

forming a first insulating film over the first conductive film;

forming an oxide semiconductor layer that comprises a channel formation region over the first insulating film;

forming a source electrode and a drain electrode by patterning a second conductive film formed over the oxide semiconductor layer, whereby a top surface of a first region of the oxide semiconductor layer that is located between the source electrode and the drain electrode is etched to have a smaller thickness than a second region of the oxide semiconductor layer that is below the source electrode or the drain electrode;

forming a second insulating film over the oxide semiconductor layer, the source electrode, and the drain electrode; and

forming a transparent film over the second insulating film by a sputtering method,

wherein the second insulating film is an oxide insulating film.

19. The method according to claim 18, wherein the oxide semiconductor layer includes indium, zinc, and a metal different from indium and zinc.

20. The method according to claim 18, wherein the transparent film is a conductive film.

21. The method according to claim 18, further comprising:

performing a heat treatment on the oxide semiconductor layer.

22. The method according to claim 18, wherein the second insulating film is in contact with the oxide semiconductor layer and the transparent film.

23. The method according to claim 18, wherein the transparent film includes indium.

24. The method according to claim 18, wherein the transparent film includes zinc.