Manufacturing method of semiconductor device

• US 9,166,026 B2
• Filed: 09/12/2013
• Issued: 10/20/2015
• Est. Priority Date: 01/12/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Potter, Roy
• Assistant Examiner(s): PATTON, PAUL E
• Application Number:
  US14/025,040
• Publication Number:
  US 20140080253A1
• Time in Patent Office: 768 Days
• Field of Search: 257/43, 257/E29.296, 257/E21.46, 438/104
• US Class Current: 1/1
• 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 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

Abstract

A manufacturing method of a semiconductor device includes the steps of: forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming an oxide semiconductor film; performing heat treatment to form a second oxide semiconductor film after the step of forming the first oxide semiconductor film; forming a first conductive film; forming a first resist mask including regions whose thicknesses are different; etching the second oxide semiconductor film and the first conductive film using the first resist mask to form a third oxide semiconductor film and a second conductive film; reducing the size of the first resist mask to form a second resist mask; selectively etching the second conductive film using the second resist mask to remove a part of the second conductive film so that a source electrode and a drain electrode are formed.

Claims

1. A method for manufacturing a semiconductor device, the method 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 over the gate insulating film;

forming a conductive film over the oxide semiconductor film;

etching the oxide semiconductor film and the conductive film in the same step to form an oxide semiconductor layer over the gate insulating film and a conductive layer over the oxide semiconductor layer;

etching the conductive layer with a dry process so as to reveal a top surface of the oxide semiconductor layer to form a source electrode and a drain electrode over the oxide semiconductor layer,

wherein an outline of the oxide semiconductor layer is located outside an outline of the source electrode and an outline of the drain electrode in a distance greater than or equal to 1 μ

m and less than or equal to 10 μ

m, and

wherein the gate insulating film is an insulating film that can release oxygen by heating.

2. The method according to claim 1, wherein the oxide semiconductor film comprises at least any one of indium, gallium, and zinc.

3. The method according to claim 1, further comprising the step of performing a heat treatment on the oxide semiconductor film at a temperature greater than or equal to 250°

C. and lower than or equal to 450°

C.

4. The method according to claim 1, wherein the oxide semiconductor layer comprises hydrogen with a concentration of 5×

10¹⁸ atoms/cm³ or lower.

5. A method for manufacturing a semiconductor device, the method 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 over the gate insulating film;

forming a first conductive film over the oxide semiconductor film;

forming a second conductive film over the first conductive film;

etching the oxide semiconductor film, the first conductive film, and the second conductive film in the same step to form an oxide semiconductor layer over the gate insulating film, a first conductive layer over the oxide semiconductor layer, and a second conductive layer over the first conductive layer;

etching the first conductive layer and the second conductive layer to form a source electrode and a drain electrode over the oxide semiconductor layer, a first low-resistance film between the source electrode and the oxide semiconductor layer, and a second low-resistance film between the drain electrode and the oxide semiconductor layer,

wherein an outline of the oxide semiconductor layer is located outside an outline of the source electrode and an outline of the drain electrode,

wherein the gate insulating film is an insulating film that can release oxygen by heating, and

wherein the first low-resistance film and the second low-resistance film have a resistivity higher than the source electrode and the drain electrode and lower than the oxide semiconductor layer.

6. The method according to claim 5, wherein the oxide semiconductor film comprises at least any one of indium, gallium, and zinc.

7. The method according to claim 5, further comprising the step of performing a heat treatment on the oxide semiconductor film at a temperature greater than or equal to 250°

C. and lower than or equal to 450°

C.

8. The method according to claim 5, wherein the oxide semiconductor layer comprises hydrogen with a concentration of 5×

10¹⁸ atoms/cm³ or lower.

9. The method according to claim 5, wherein the first low-resistance film and the second low-resistance film comprise a conductive metal oxide.

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

forming a gate electrode over a substrate;

forming a first gate insulating film over the gate electrode;

forming an oxide semiconductor film over the first gate insulating film;

forming a conductive film over the oxide semiconductor film;

etching the oxide semiconductor film and the conductive film in the same step to form an oxide semiconductor layer over the first gate insulating film and a conductive layer over the oxide semiconductor layer;

etching the conductive layer with a dry process so as to reveal a top surface of the oxide semiconductor layer to form a source electrode and a drain electrode over the oxide semiconductor layer;

forming a second insulating film over the source electrode and the drain electrode;

forming an electrode over the second insulating film,

wherein the electrode overlaps with the gate electrode,

wherein an outline of the oxide semiconductor layer is located outside an outline of the source electrode and an outline of the drain electrode in a distance greater than or equal to 1 μ

m and less than or equal to 10 μ

m, and

wherein the first gate insulating film is an insulating film that can release oxygen by heating.

11. The method according to claim 10, wherein the oxide semiconductor film comprises at least any one of indium, gallium, and zinc.

12. The method according to claim 10, further comprising the step of performing a heat treatment on the oxide semiconductor film at a temperature greater than or equal to 250°

C. and lower than or equal to 450°

C.

13. The method according to claim 10, wherein the oxide semiconductor layer comprises hydrogen with a concentration of 5×

10¹⁸ atoms/cm³ or lower.

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

forming a gate electrode over a substrate;

forming a first gate insulating film over the gate electrode;

forming an oxide semiconductor film over the first gate insulating film;

forming a first conductive film over the oxide semiconductor film;

forming a second conductive film over the first conductive film;

etching the oxide semiconductor film, the first conductive film, and the second conductive film in the same step to form an oxide semiconductor layer over the first gate insulating film, a first conductive layer over the oxide semiconductor layer, and a second conductive layer over the first conductive layer;

etching the first conductive layer and the second conductive layer to form a source electrode and a drain electrode over the oxide semiconductor layer, a first low-resistance film between the source electrode and the oxide semiconductor layer, and a second low-resistance film between the drain electrode and the oxide semiconductor layer;

forming a second insulating film over the source electrode and the drain electrode;

forming an electrode over the second insulating film,

wherein the electrode overlaps with the gate electrode,

wherein an outline of the oxide semiconductor layer is located outside an outline of the source electrode and an outline of the drain electrode,

wherein the first gate insulating film is an insulating film that can release oxygen by heating, and

wherein the first low-resistance film and the second low-resistance film have a resistivity higher than the source electrode and the drain electrode and lower than the oxide semiconductor layer.

15. The method according to claim 14, wherein the oxide semiconductor film comprises at least any one of indium, gallium, and zinc.

16. The method according to claim 14, further comprising the step of performing a heat treatment on the oxide semiconductor film at a temperature greater than or equal to 250°

C. and lower than or equal to 450°

C.

17. The method according to claim 14, wherein the oxide semiconductor layer comprises hydrogen with a concentration of 5×

10¹⁸ atoms/cm³ or lower.

18. The method according to claim 14, wherein the first low-resistance film and the second low-resistance film comprise a conductive metal oxide.