Method for manufacturing semiconductor device

• US 9,722,091 B2
• Filed: 09/10/2015
• Issued: 08/01/2017
• Est. Priority Date: 09/12/2014
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US14/850,026
• Publication Number:
  US 20160079430A1
• Time in Patent Office: 691 Days
• Field of Search: None
• CPC Class Codes: H01L 21/02323 introduction of oxygen
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/31155 by ion implantation
• 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 21/8258 the substrate being a semiconductor, using a combination of technologies covered by H01L21/8206, H01L21/8213 , H01L21/822, H01L21/8252, H01L21/8254 or H01L21/8256
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/1207 combined with devices in contact with the semiconductor body, i.e. bulk/SOI hybrid circuits
• 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 27/14643 Photodiode arrays; MOS imagers
• 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 29/78648 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
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

Provided is a transistor containing a semiconductor with low density of defect states, a transistor having a small subthreshold swing value, a transistor having a small short-channel effect, a transistor having normally-off electrical characteristics, a transistor having a low leakage current in an off state, a transistor having excellent electrical characteristics, a transistor having high reliability, or a transistor having excellent frequency characteristics. An insulator is formed, a layer is formed over the insulator, oxygen is added to the insulator through the layer, the layer is removed, an oxide semiconductor is formed over the insulator to which the oxygen is added, and a semiconductor element is formed using the oxide semiconductor.

Claims

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

forming an insulator;

forming a layer over the insulator;

adding oxygen to the insulator through the layer;

after adding the oxygen, removing the layer;

after removing the layer, forming an oxide semiconductor over the insulator to which the oxygen is added; and

forming a semiconductor element comprising the oxide semiconductor.

2. The method for manufacturing a semiconductor device, according to claim 1, wherein the layer contains a second oxide semiconductor.

3. The method for manufacturing a semiconductor device, according to claim 1, wherein the layer is removed by wet etching.

4. The method for manufacturing a semiconductor device, according to claim 1, wherein the insulator is an oxide comprising silicon.

5. The method for manufacturing a semiconductor device, according to claim 1, further comprising the step of performing heat treatment after forming the oxide semiconductor.

6. The method for manufacturing a semiconductor device, according to claim 5, wherein hydrogen in the oxide semiconductor and oxygen in the insulator are made to react with each other by the heat treatment to be released as water.

7. The method for manufacturing a semiconductor device, according to claim 1, wherein the oxygen is added by an ion implantation method.

8. The method for manufacturing a semiconductor device, according to claim 1, wherein the semiconductor element is a transistor.

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

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

forming an oxide insulator;

forming a layer over the oxide insulator;

adding oxygen to the oxide insulator through the layer;

after adding the oxygen, removing the layer;

after removing the layer, forming an oxide semiconductor over the oxide insulator to which the oxygen is added; and

forming a semiconductor element comprising the oxide semiconductor.

11. The method for manufacturing a semiconductor device, according to claim 10, wherein the layer contains a second oxide semiconductor.

12. The method for manufacturing a semiconductor device, according to claim 10, wherein the layer is removed by wet etching.

13. The method for manufacturing a semiconductor device, according to claim 10, further comprising the step of performing heat treatment after forming the oxide semiconductor.

14. The method for manufacturing a semiconductor device, according to claim 13, wherein hydrogen in the oxide semiconductor and oxygen in the oxide insulator are made to react with each other by the heat treatment to be released as water.

15. The method for manufacturing a semiconductor device, according to claim 10, wherein the oxygen is added by an ion implantation method.

16. The method for manufacturing a semiconductor device, according to claim 10, wherein the semiconductor element is a transistor.

17. The method for manufacturing a semiconductor device according to claim 10, wherein the oxide semiconductor comprises indium, gallium, and zinc.

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

forming an insulating layer containing an oxide;

forming a sacrificial layer containing an oxide semiconductor over the insulating layer;

adding molecular ions containing oxygen to the insulating layer through the sacrificial layer, so that excess oxygen exists in the insulating layer;

etching the sacrificial layer to remove the sacrificial layer from the insulating layer; and

forming an oxide semiconductor layer over the insulating layer; and

performing a heat treatment on the oxide semiconductor layer, so that the excess oxygen in the insulating layer moves to the oxide semiconductor layer.

19. The method according to claim 18, wherein the oxide in the insulating layer contains at least one selected from Al, Mg, Si, Ga, Ge, Y, Zr, La, Nd, Hf and Ta.

20. The method according to claim 18, wherein:

the oxide semiconductor in the sacrificial layer is an In—

Ga—

Zn oxide, and

the In—

Ga—

Zn oxide contains gallium twice or more as much as indium in an atomic ratio.

21. The method according to claim 18, wherein the step of etching is performed by wet etching.

22. The method according to claim 18, wherein a hydrogen concentration of the oxide semiconductor layer after the heat treatment is in a range of 1×

10¹⁶ atoms/cm³ or higher and 5×

10¹⁸ atoms/cm³ or lower.