METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20140154837A1
• Filed: 12/02/2013
• Published: 06/05/2014
• Est. Priority Date: 12/03/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Granted Patent: US 9,349,593 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• CPC Class Codes: H01L 21/02488 Insulating materials
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

To improve electric characteristics of a semiconductor device including an oxide semiconductor. Alternatively, to improve reliability of a semiconductor device including an oxide semiconductor. In a transistor including a first oxide film, an oxide semiconductor film, a pair of electrodes in contact with the oxide semiconductor film, and a second oxide film in contact with the oxide semiconductor film and the pair of electrodes, oxygen is added to the first oxide film and the second oxide film in contact with the oxide semiconductor film and the pair of electrodes, so that oxygen vacancies are reduced. The oxygen is diffused to the oxide semiconductor film by heat treatment or the like; thus, oxygen vacancies in the oxide semiconductor film are reduced.

Claims

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

forming an oxide film over a substrate;

adding oxygen to the oxide film;

forming an oxide semiconductor film over the oxide film after adding oxygen to the oxide film;

performing heat treatment;

etching part of the oxide film and part of the oxide semiconductor film;

forming a pair of electrodes over the oxide semiconductor film after etching the part of the oxide film and the part of the oxide semiconductor film;

forming a gate insulating film over the oxide semiconductor film and the pair of electrodes; and

forming a gate electrode over the gate insulating film.

2. The method for manufacturing a semiconductor device, according to claim 1, wherein the oxide semiconductor film comprises at least one of In, Ga and Zn.

3. The method for manufacturing a semiconductor device, according to claim 1, wherein a distance between a bottom of a conduction band of the oxide film and a vacuum level is smaller than a distance between a bottom of a conduction band of the oxide semiconductor film and the vacuum level.

4. The method for manufacturing a semiconductor device, according to claim 1, wherein a difference between energy of a bottom of a conduction band of the oxide film and energy of a bottom of a conduction band of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

5. The method for manufacturing a semiconductor device, according to claim 1, wherein the oxygen is added to the oxide film by an ion implantation method, an ion doping method, or plasma treatment.

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

forming a first oxide film over a substrate;

adding oxygen to the first oxide film;

forming an oxide semiconductor film over the first oxide film after adding oxygen to the first oxide film;

etching part of the first oxide film and part of the oxide semiconductor film;

forming a pair of electrodes over the oxide semiconductor film after etching the part of the first oxide film and the part of the oxide semiconductor film;

forming a second oxide film over the oxide semiconductor film and the pair of electrodes;

performing heat treatment after forming the second oxide film;

forming a gate insulating film over the second oxide film; and

forming a gate electrode over the gate insulating film.

7. The method for manufacturing a semiconductor device, according to claim 6, wherein the oxide semiconductor film comprises at least one of In, Ga and Zn.

8. The method for manufacturing a semiconductor device, according to claim 6,

wherein a distance between a bottom of a conduction band of the first oxide film and a vacuum level is smaller than a distance between a bottom of a conduction band of the oxide semiconductor film and the vacuum level, and

wherein a distance between a bottom of a conduction band of the second oxide film and the vacuum level is smaller than the distance between the bottom of the conduction band of the oxide semiconductor film and the vacuum level.

9. The method for manufacturing a semiconductor device, according to claim 6,

wherein a difference between energy of a bottom of a conduction band of the first oxide film and energy of a bottom of a conduction band of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV, and

wherein a difference between energy of a bottom of a conduction band of the second oxide film and the energy of the bottom of the conduction band of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

10. The method for manufacturing a semiconductor device, according to claim 6, wherein the oxygen is added to the first oxide film by an ion implantation method, an ion doping method, or plasma treatment.

11. The method for manufacturing a semiconductor device, according to claim 6, wherein the oxygen is added to the second oxide film by an ion implantation method, an ion doping method, or plasma treatment.

12. The method for manufacturing a semiconductor device, according to claim 6, wherein heat treatment is performed after forming the oxide semiconductor film over the first oxide film and before forming the second oxide film over the oxide semiconductor film and the pair of electrodes.

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 a first oxide film over the gate insulating film;

adding oxygen to the first oxide film;

forming an oxide semiconductor film over the first oxide film after adding oxygen to the first oxide film;

etching part of the first oxide film and part of the oxide semiconductor film;

forming a pair of electrodes over the oxide semiconductor film after etching the part of the first oxide film and the part of the oxide semiconductor film;

forming a second oxide film over the pair of the electrodes and the oxide semiconductor film;

adding oxygen to the second oxide film;

performing heat treatment; and

forming an insulating film over the second oxide film to which the oxygen is added.

14. The method for manufacturing a semiconductor device, according to claim 13, wherein the oxide semiconductor film comprises at least one of In, Ga and Zn.

15. The method for manufacturing a semiconductor device, according to claim 13,

wherein a distance between a bottom of a conduction band of the first oxide film and a vacuum level is smaller than a distance between a bottom of a conduction band of the oxide semiconductor film and the vacuum level, and

wherein a distance between a bottom of a conduction band of the second oxide film and the vacuum level is smaller than the distance between the bottom of the conduction band of the oxide semiconductor film and the vacuum level.

16. The method for manufacturing a semiconductor device, according to claim 13,

wherein a difference between energy of a bottom of a conduction band of the first oxide film and energy of a bottom of a conduction band of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV, and

wherein a difference between energy of a bottom of a conduction band of the second oxide film and the energy of the bottom of the conduction band of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

17. The method for manufacturing a semiconductor device, according to claim 13, wherein the oxygen is added to the first oxide film by an ion implantation method, an ion doping method, or plasma treatment.

18. The method for manufacturing a semiconductor device, according to claim 13, wherein the oxygen is added to the second oxide film by an ion implantation method, an ion doping method, or plasma treatment.

19. The method for manufacturing a semiconductor device, according to claim 13, wherein heat treatment is performed after forming the oxide semiconductor film over the first oxide film and before forming the second oxide film over the oxide semiconductor film and the pair of electrodes.