SEMICONDUCTOR DEVICE

• US 20100117075A1
• Filed: 11/05/2009
• Published: 05/13/2010
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: AKIMOTO, Kengo, YAMAZAKI, Shunpei
• Granted Patent: US 8,502,216 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• 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 29/66742 Thin film unipolar transistors
• 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 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• 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

An object is to prevent an impurity such as moisture and oxygen from being mixed into an oxide semiconductor and suppress variation in semiconductor characteristics of a semiconductor device in which an oxide semiconductor is used. Another object is to provide a semiconductor device with high reliability. A gate insulating film provided over a substrate having an insulating surface, a source and a drain electrode which are provided over the gate insulating film, a first oxide semiconductor layer provided over the source electrode and the drain electrode, and a source and a drain region which are provided between the source electrode and the drain electrode and the first oxide semiconductor layer are provided. A barrier film is provided in contact with the first oxide semiconductor layer.

Claims

1. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating film over the gate electrode layer;

a source electrode and a drain electrode over the gate insulating film;

a first oxide semiconductor layer over the source electrode and the drain electrode;

a source region between the source electrode and the first oxide semiconductor layer, and a drain region between the drain electrode and the first oxide semiconductor layer; and

a barrier film in contact with the first oxide semiconductor layer.

4. The semiconductor device according to any one of claims 1 to 3, wherein the barrier film includes one or more of an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, and an aluminum nitride oxide film.

5. The semiconductor device according to any one of claims 1 to 3, wherein a thickness of the barrier film is greater than or equal to 1 nm and less than or equal to 200 nm.

6. The semiconductor device according to any one of claims 1 to 3, wherein the gate insulating film includes one or more of an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, and an aluminum nitride oxide film.

7. The semiconductor device according to any one of claims 1 to 3, wherein the first oxide semiconductor layer includes indium, gallium, and zinc.

8. The semiconductor device according to any one of claims 1 to 3, wherein the source region and the drain region are formed from second oxide semiconductor layers having higher conductivity than the first oxide semiconductor layer.

9. The semiconductor device according to claim 8, wherein the second oxide semiconductor layers include indium, gallium, and zinc.

2. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating film over the gate electrode layer;

a first oxide semiconductor layer over the gate electrode layer with the gate insulating film interposed therebetween;

a source region and a drain region which are provided separately from each other over the first oxide semiconductor layer;

a source electrode over and in contact with the source region, and a drain electrode over and in contact with the drain region; and

a barrier film in contact with a part of the first oxide semiconductor layer.

3. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating film over the gate electrode layer;

a first oxide semiconductor layer over the gate insulating film;

a channel protective layer provided in a region overlapping with a channel formation region of the first oxide semiconductor layer;

a source electrode and a drain electrode over the first oxide semiconductor layer;

a source region between the source electrode and the first oxide semiconductor layer, and a drain region between the drain electrode and the first oxide semiconductor layer; and

a barrier film in contact with a part of the channel protective layer.