Method for manufacturing semiconductor device

• US 7,915,075 B2
• Filed: 10/16/2009
• Issued: 03/29/2011
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Muraoka, Taiga, Sasagawa, Shinya, Suzawa, Hideomi
• Primary Examiner(s): Ghyka; Alexander G
• Assistant Examiner(s): MUSTAPHA, ABDULFATTAH B
• Application Number:
  US12/580,512
• Publication Number:
  US 20100099216A1
• Time in Patent Office: 529 Days
• Field of Search: 438/104, 438/158, 257/E21.414
• US Class Current: 438/104
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 take precedence
• CPC Class Codes: H01L 21/465 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/469
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• 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 29/7869 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
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

An object is to establish a processing technique in manufacture of a semiconductor device in which an oxide semiconductor is used. A gate electrode is formed over a substrate, a gate insulating layer is formed over the gate electrode, an oxide semiconductor layer is formed over the gate insulating layer, the oxide semiconductor layer is processed by wet etching to form an island-shaped oxide semiconductor layer, a conductive layer is formed to cover the island-shaped oxide semiconductor layer, the conductive layer is processed by dry etching to form a source electrode, and a drain electrode and part of the island-shaped oxide semiconductor layer is removed by dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

Claims

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming an oxide semiconductor layer over the gate insulating layer;

processing the oxide semiconductor layer by wet etching to form an island-shaped oxide semiconductor layer;

forming a conductive layer over the island-shaped oxide semiconductor layer;

processing the conductive layer by first dry etching to form a source electrode and a drain electrode; and

removing a part of the island-shaped oxide semiconductor layer by second dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

2. The method for manufacturing a semiconductor device, according to claim 1, wherein the oxide semiconductor layer includes indium, gallium, and zinc.

3. The method for manufacturing a semiconductor device, according to claim 1, wherein the conductive layer is formed using a material whose etching rate in the dry etching is higher then that of a material used for the oxide semiconductor layer.

4. The method for manufacturing a semiconductor device, according claim 1, wherein the dry etching is performed using a gas including chlorine.

5. The method for manufacturing a semiconductor device, according to claim 4,

wherein the gate insulating layer is formed using a material including silicon oxide, and

wherein the gas including chlorine includes oxygen.

6. The method for manufacturing a semiconductor device, according to claim 5, a content of the oxygen is 15 volume % or more of the gas including chlorine.

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming an oxide semiconductor layer over the gate insulating layer;

processing the oxide semiconductor layer by wet etching to form an island-shaped oxide semiconductor layer;

forming a conductive layer over the island-shaped oxide semiconductor layer;

processing the conductive layer by dry etching to form a source electrode and a drain electrode; and

removing a part of the island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

8. The method for manufacturing a semiconductor device, according to claim 7, wherein the oxide semiconductor layer includes indium, gallium, and zinc.

9. The method for manufacturing a semiconductor device, according to claim 7, wherein the conductive layer is formed using a material whose etching rate in the dry etching is higher then that of a material used for the oxide semiconductor layer.

10. The method for manufacturing a semiconductor device, according claim 7, wherein the dry etching is performed using a gas including chlorine.

11. The method for manufacturing a semiconductor device, according to claim 10,

wherein the gate insulating layer is formed using a material including silicon oxide, and

wherein the gas including chlorine includes oxygen.

12. The method for manufacturing a semiconductor device, according to claim 11, a content of the oxygen is 15 volume % or more of the gas including chlorine.

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming a first oxide semiconductor layer over the gate insulating layer;

forming a second oxide semiconductor layer over the first oxide semiconductor layer, wherein a conductivity of the second oxide semiconductor layer is higher than a conductivity of the first oxide semiconductor layer;

processing the first oxide semiconductor layer and the second oxide semiconductor layer by wet etching to form a first island-shaped oxide semiconductor layer and a second island-shaped oxide semiconductor layer;

forming a conductive layer over the second island-shaped oxide semiconductor layer;

processing the conductive layer by first dry etching to form a source electrode and a drain electrode; and

removing a part of the first island-shaped oxide semiconductor layer and a part of the second island-shaped oxide semiconductor layer by second dry etching to form a recessed portion in the first island-shaped oxide semiconductor layer.

14. The method for manufacturing a semiconductor device, according to claim 13, wherein the first oxide semiconductor layer and the second oxide semiconductor layer each include indium, gallium, and zinc.

15. The method for manufacturing a semiconductor device, according to claim 13, wherein the conductive layer is formed using a material whose etching rate in the dry etching is higher than that of a material used for the second oxide semiconductor layer.

16. The method for manufacturing a semiconductor device, according claim 13, wherein the dry etching is performed using a gas including chlorine.

17. The method for manufacturing a semiconductor device, according to claim 16,

wherein the gate insulating layer is formed using a material including silicon oxide, and

wherein the gas including chlorine includes oxygen.

18. The method for manufacturing a semiconductor device, according to claim 17, a content of the oxygen is 15 volume % or more of the gas including chlorine.

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming a first oxide semiconductor layer over the gate insulating layer;

forming a second oxide semiconductor layer whose conductivity is higher than a conductivity of the first oxide semiconductor layer, over the first oxide semiconductor layer;

processing the first oxide semiconductor layer and the second oxide semiconductor layer by wet etching to form a first island-shaped oxide semiconductor layer and a second island-shaped oxide semiconductor layer;

forming a conductive layer over the second island-shaped oxide semiconductor layer; and

processing the conductive layer by dry etching to form a source electrode and a drain electrode; and

removing a part of the first island-shaped oxide semiconductor layer and a part of the second island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the first island-shaped oxide semiconductor layer.

20. The method for manufacturing a semiconductor device, according to claim 19, wherein the first oxide semiconductor layer and the second oxide semiconductor layer each include indium, gallium, and zinc.

21. The method for manufacturing a semiconductor device, according to claim 19, wherein the conductive layer is formed using a material whose etching rate in the dry etching is higher than that of a material used for the second oxide semiconductor layer.

22. The method for manufacturing a semiconductor device, according claim 19, wherein the dry etching is performed using a gas including chlorine.

23. The method for manufacturing a semiconductor device, according to claim 22,

wherein the gate insulating layer is formed using a material including silicon oxide, and

wherein the gas including chlorine includes oxygen.

24. The method for manufacturing a semiconductor device, according to claim 23, a content of the oxygen is 15 volume % or more of the gas including chlorine.

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming an island-shaped oxide semiconductor layer over the gate insulating layer;

forming a conductive layer over the island-shaped oxide semiconductor layer; and

processing the conductive layer by dry etching using a gas including chlorine and oxygen, to form a source electrode and a drain electrode; and

removing part of the island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

26. The method for manufacturing a semiconductor device, according to claim 25, wherein the island-shaped oxide semiconductor layer includes indium, gallium, and zinc.

27. The method for manufacturing a semiconductor device, according to claim 25, wherein the conductive layer is formed using a material whose etching rate in the dry etching is higher then that of a material used for the island-shaped oxide semiconductor layer.

28. The method for manufacturing a semiconductor device, according to claim 25, wherein a content of the oxygen is 15 volume % or more of the gas including chlorine and oxygen.