# US 8,785,258 B2 · Method for manufacturing semiconductor device

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- Number: US 8,785,258 B2
- Document ID: US8785258B2
- Status: Granted
- Kind: B2
- Application number: 13/711,022
- Filed: 2012-12-11
- Published: 2013-06-20
- Granted: 2014-07-22
- Earliest claimed: 2011-12-20
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Semiconductor Energy Laboratory Co., Ltd.
- Inventors: Shunpei Yamazaki
- Web page: https://patentgrep.com/patent/US8785258B2

## CPC

- H10D 99/00: Subject matter not provided for in other groups of this subclass
- H10D 30/031: {of thin-film transistors [TFT]}
- H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate}
- H10D 30/6756: {Amorphous oxide semiconductors}
- H10D 86/423: {comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO}
- H10D 86/60: wherein the TFTs are in active matrices
- H10D 30/0312: {characterised by the gate electrodes}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A highly reliable semiconductor device which includes a transistor including an oxide semiconductor is provided. In the semiconductor device including a bottom-gate transistor including an oxide semiconductor layer, a stacked layer of an insulating layer and an aluminum film is provided in contact with the oxide semiconductor layer. Oxygen doping treatment is performed in such a manner that oxygen is introduced to the insulating layer and the aluminum film from a position above the aluminum film, whereby a region containing oxygen in excess of the stoichiometric composition is formed in the insulating layer, and the aluminum film is oxidized to form an aluminum oxide film.

## Claims

### Claim 1

A method for manufacturing a semiconductor device comprising the steps of:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer overlapping with the gate electrode layer with the gate insulating layer interposed therebetween;
forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor layer:
forming an insulating layer over the source electrode layer and the drain electrode layer and in contact with the oxide semiconductor layer;
forming an aluminum film in contact with the insulating layer; and
performing an oxygen doping treatment on the insulating layer and the aluminum film, so that at least a portion of the aluminum film is oxidized to be an aluminum oxide film.

### Claim 2 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, further comprising a step of performing heat treatment on the aluminum film after the step of the performing an oxygen doing treatment.

### Claim 3 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the aluminum film is oxidized to be an aluminum oxide layer.

### Claim 4 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the insulating layer comprises an oxygen excess region.

### Claim 5 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the insulating layer comprises a layer containing nitrogen.

### Claim 6 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, further comprising a step of performing heat treatment on the insulating layer before the aluminum film is formed.

### Claim 7 (depends on 1)

The method for manufacturing a semiconductor device according to claim 1, wherein the gate insulating layer comprises an oxygen excess region.

### Claim 8 (depends on 7)

The method for manufacturing a semiconductor device according to claim 7, wherein the oxygen excess region is formed by performing an oxygen doping treatment on the gate insulating layer.

### Claim 9

A method for manufacturing a semiconductor device comprising the steps of:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
performing heat treatment on the gate insulating layer to reduce hydrogen in the gate insulating layer;
forming an oxide semiconductor layer overlapping with the gate electrode layer with the gate insulating layer interposed therebetween;
forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor layer:
forming an insulating layer over the source electrode layer and the drain electrode layer and in contact with the oxide semiconductor layer;
forming an aluminum film in contact with the insulating layer; and
performing an oxygen doping treatment on the insulating layer and the aluminum film, so that at least a portion of the aluminum film is oxidized to be an aluminum oxide film.

### Claim 10 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, further comprising a step of performing heat treatment on the aluminum film after the step of the performing an oxygen doing treatment.

### Claim 11 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, wherein the aluminum film is oxidized to be an aluminum oxide layer.

### Claim 12 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, wherein the insulating layer comprises an oxygen excess region.

### Claim 13 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, wherein the insulating layer comprises a layer containing nitrogen.

### Claim 14 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, further comprising a step of performing heat treatment on the insulating layer before the aluminum film is formed.

### Claim 15 (depends on 9)

The method for manufacturing a semiconductor device according to claim 9, wherein the gate insulating layer comprises an oxygen excess region.

### Claim 16 (depends on 15)

The method for manufacturing a semiconductor device according to claim 15, wherein the oxygen excess region is formed by performing an oxygen doping treatment on the gate insulating layer.