Semiconductor device and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9252279-B2
Application number	US-201213592870-A
Country	US
Kind code	B2
Filing date	Aug 23, 2012
Priority date	Aug 31, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

To provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and has high reliability. To provide a method for manufacturing the semiconductor device. The semiconductor device includes a gate electrode, a gate insulating film formed over the gate electrode, an oxide semiconductor film formed over the gate insulating film, a source electrode and a drain electrode formed over the oxide semiconductor film, and a protective film. The protective film includes a metal oxide film, and the metal oxide film has a film density of higher than or equal to 3.2 g/cm 3 .

First claim

What is claimed is:

1. A semiconductor device comprising:
an oxide semiconductor film over an insulating surface;
a source electrode and a drain electrode over the oxide semiconductor film;
an oxide insulating film over and in contact with the oxide semiconductor film, the source electrode, and the drain electrode; and
a first metal oxide film over the oxide insulating film,
wherein the first metal oxide film has a film density of higher than or equal to 3.2 g/cm 3 , and
wherein the first metal oxide film is a Ga—Zn-based oxide film.

2. The semiconductor device according to claim 1 , further comprising a second metal oxide film in contact with the oxide semiconductor film.

3. The semiconductor device according to claim 1 ,
wherein the first metal oxide film is a film including aluminum oxide.

4. The semiconductor device according to claim 1 ,
wherein the oxide semiconductor film includes at least one of oxides of indium, zinc, gallium, zirconium, tin, gadolinium, titanium, and cerium.

5. A semiconductor device comprising:
a gate electrode;
a gate insulating film over the gate electrode;
an oxide semiconductor film over the gate insulating film;
a source electrode and a drain electrode over the oxide semiconductor film; and
a protective film over the oxide semiconductor film, the source electrode, and the drain electrode,
wherein the protective film is a stack in which a first metal oxide film is provided over an oxide insulating film,
wherein the oxide insulating film is in contact with the oxide semiconductor film,
wherein the first metal oxide film has a film density of higher than or equal to 3.2 g/cm 3 , and
wherein the first metal oxide film is a Ga—Zn-based oxide film.

6. The semiconductor device according to claim 5 ,
wherein the first metal oxide film is a film including aluminum oxide.

7. The semiconductor device according to claim 5 , further comprising a conductive film in contact with the first metal oxide film of the protective film.

8. The semiconductor device according to claim 7 ,
wherein the conductive film includes at least one of zinc oxide, indium tin oxide, titanium oxide, aluminum, and titanium.

9. The semiconductor device according to claim 5 ,
wherein the oxide semiconductor film includes at least one of oxides of indium, zinc, gallium, zirconium, tin, gadolinium, titanium, and cerium.

10. The semiconductor device according to claim 5 , further comprising a second metal oxide film over and in contact with the gate insulating film.

11. The semiconductor device according to claim 5 , further comprising a base insulating film under and in contact with the gate electrode,
wherein the base insulating film includes a third metal oxide film in contact with the gate electrode, and
wherein a film density of the third metal oxide film is higher than or equal to 3.2 g/cm 3 .

Assignees

• Watanabe Masahiro
• Mashiyama Mitsuo
• Handa Takuya
• Okazaki Kenichi
• Semiconductor Energy Lab

Inventors

• Watanabe Masahiro
• Mashiyama Mitsuo
• Handa Takuya
• Okazaki Kenichi

Classifications

• H10D62/875

  being semiconductor metal oxide, e.g. InGaZnO (Group II-VI materials H10D62/86; Group I-VI materials H10D62/871; Pb compounds or alloys H10D62/874) · CPC title

• H10D30/6755 Primary

  Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate · CPC title

• H10D30/6758

  characterised by the insulating substrates · CPC title

• H10D30/6704 Primary

  having supplementary regions or layers in the thin films or in the insulated bulk substrates for controlling properties of the device · CPC title

• H10D62/80

  characterised by the materials · CPC title