# US 8,772,094 B2 · Method for manufacturing semiconductor device

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- Number: US 8,772,094 B2
- Document ID: US8772094B2
- Status: Granted
- Kind: B2
- Application number: 13/681,895
- Filed: 2012-11-20
- Published: 2013-05-30
- Granted: 2014-07-08
- Earliest claimed: 2011-11-25
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Semiconductor Energy Laboratory Co., Ltd.
- Inventors: Naoto Yamade; Junichi Koezuka; Shunpei Yamazaki
- Web page: https://patentgrep.com/patent/US8772094B2

## CPC

- H10D 30/021: {of FETs having insulated gates [IGFET]}
- H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate}
- H10D 99/00: Subject matter not provided for in other groups of this subclass
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A highly reliable semiconductor device that includes a transistor including an oxide semiconductor is provided. In a manufacturing process of a semiconductor device that includes a bottom-gate transistor including an oxide semiconductor, an insulating film which is in contact with an oxide semiconductor film is subjected to dehydration or dehydrogenation treatment by heat treatment and oxygen doping treatment in this order. The insulating film which is in contact with the oxide semiconductor film refers to a gate insulating film provided under the oxide semiconductor film and an insulating film which is provided over the oxide semiconductor film and functions as a protective insulating film. The gate insulating film and/or the insulating film are/is subjected to dehydration or dehydrogenation treatment by heat treatment and oxygen doping treatment in this order.

## Claims

### Claim 1

A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode layer;
forming a gate insulating film over the gate electrode layer;
removing water or hydrogen from the gate insulating film by performing a first heat treatment on the gate insulating film;
supplying oxygen to the gate insulating film by performing a first oxygen doping treatment on the gate insulating film after performing the first heat treatment;
forming an oxide semiconductor film over a region of the gate insulating film, which overlaps with the gate electrode layer; and
forming a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor film.

### Claim 2 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, further comprising the step of performing a second oxygen doping treatment on the gate insulating film before performing the first heat treatment.

### Claim 3 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, further comprising performing a second heat treatment on the gate insulating film and the oxide semiconductor film after forming the oxide semiconductor film.

### Claim 4 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the gate insulating film is formed by a chemical vapor deposition method.

### Claim 5 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein a temperature of the first heat treatment is higher than or equal to 300° C. and lower than or equal to 700° C.

### Claim 6 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the first oxygen doping treatment is performed by any one of ion implantation method, ion doping method, plasma immersion ion implantation method, and plasma treatment.

### Claim 7

A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode layer;
forming a gate insulating film over the gate electrode layer;
forming an oxide semiconductor film over a region of the gate insulating film, which overlaps with the gate electrode layer;
forming a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor film;
forming an insulating film over the oxide semiconductor film, the source electrode layer, and the drain electrode layer and in contact with the oxide semiconductor film;
removing water or hydrogen from the insulating film by performing a first heat treatment on the insulating film; and
supplying oxygen to the insulating film by performing a first oxygen doping treatment on the insulating film after performing the first heat treatment.

### Claim 8 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, further comprising the step of performing a second oxygen doping treatment on the gate insulating film before performing the first heat treatment.

### Claim 9 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, further comprising the steps of:
forming an aluminum oxide film covering the gate insulating film, the oxide semiconductor film, and the insulating film, and
performing a second heat treatment on the gate insulating film, the oxide semiconductor film, and the insulating film after forming the aluminum oxide film.

### Claim 10 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, wherein the insulating film is formed by a chemical vapor deposition method.

### Claim 11 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, wherein a temperature of the first heat treatment is higher than or equal to 300° C. and lower than or equal to 700° C.

### Claim 12 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, wherein the first oxygen doping treatment is performed by any one of ion implantation method, ion doping method, plasma immersion ion implantation method, and plasma treatment.

### Claim 13

A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode layer;
forming a gate insulating film over the gate electrode layer;
removing water or hydrogen from the gate insulating film by performing a first heat treatment on the gate insulating film;
supplying oxygen to the gate insulating film by performing a first oxygen doping treatment on the gate insulating film after performing the first heat treatment;
forming an oxide semiconductor film over a region of the gate insulating film, which overlaps with the gate electrode layer;
forming a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor film;
forming an insulating film in contact with the oxide semiconductor film and over the oxide semiconductor film, the source electrode layer, and the drain electrode layer;
removing water or hydrogen from the insulating film by performing a second heat treatment on the insulating film; and
supplying oxygen to the insulating film by performing a second oxygen doping treatment on the insulating film after performing the second heat treatment.

### Claim 14 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, further comprising the step of performing a third oxygen doping treatment on the gate insulating film before performing the first heat treatment.

### Claim 15 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, further comprising the step of performing a third oxygen doping treatment on the insulating film before performing the second heat treatment.

### Claim 16 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, further comprising the steps of:
forming an aluminum oxide film covering the gate insulating film, the oxide semiconductor film, and the insulating film, and
performing a third heat treatment on the gate insulating film, the oxide semiconductor film, and the insulating film after forming the aluminum oxide film.

### Claim 17 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, wherein the gate insulating film is formed by a chemical vapor deposition method.

### Claim 18 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, wherein the insulating film is formed by a chemical vapor deposition method.

### Claim 19 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, wherein a temperature of the first heat treatment is higher than or equal to 300° C. and lower than or equal to 700° C.

### Claim 20 (depends on 13)

The method for manufacturing a semiconductor device according to claim 13, wherein the first oxygen doping treatment is performed by any one of ion implantation method, ion doping method, plasma immersion ion implantation method, and plasma treatment.