Semiconductor device and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9064853-B2
Application number	US-201213572847-A
Country	US
Kind code	B2
Filing date	Aug 13, 2012
Priority date	Aug 19, 2011
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

A semiconductor device including an oxide semiconductor and including a more excellent gate insulating film is provided. A highly reliable and electrically stable semiconductor device having a small number of changes in the film structure, the process conditions, the manufacturing apparatus, or the like from a mass production technology that has been put into practical use is provided. A method for manufacturing the semiconductor device is provided. The semiconductor device includes a gate electrode, a gate insulating film formed over the gate electrode, and an oxide semiconductor film formed over the gate insulating film. The gate insulating film includes a silicon nitride oxide film, a silicon oxynitride film formed over the silicon nitride oxide film, and a metal oxide film formed over the silicon oxynitride film. The oxide semiconductor film is formed over and in contact with the metal oxide film.

First claim

What is claimed is:

1. A semiconductor device comprising:
a gate electrode;
a gate insulating film comprising a silicon nitride oxide film over the gate electrode, a silicon oxynitride film over the silicon nitride oxide film, and a metal oxide film over the silicon oxynitride film;
an oxide semiconductor film over and in contact with the metal oxide film;
a source electrode and a drain electrode over the oxide semiconductor film; and
a protective film over and in contact with the oxide semiconductor film, the source electrode, and the drain electrode,
wherein the oxide semiconductor film comprises a c-axis aligned crystalline oxide semiconductor,
wherein the oxide semiconductor film is an In—Ga—Zn-based oxide film, and
wherein the metal oxide film is a Ga—Zn-based oxide film.

2. The semiconductor device according to claim 1 , wherein the silicon nitride oxide film has a larger thickness than the silicon oxynitride film.

3. The semiconductor device according to claim 1 , wherein the metal oxide film has a smaller thickness than the silicon nitride oxide film.

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. The semiconductor device according to claim 1 , wherein an average surface roughness of the gate insulating film is less than or equal to 1 nm.

6. A display device comprising a transistor, the transistor comprising:
a gate electrode;
a gate insulating film comprising a silicon nitride oxide film over the gate electrode, a silicon oxynitride film over the silicon nitride oxide film, and a metal oxide film over the silicon oxynitride film;
an oxide semiconductor film over and in contact with the metal oxide film;
a source electrode and a drain electrode over the oxide semiconductor film; and
a protective film over and in contact with the oxide semiconductor film, the source electrode, and the drain electrode,
wherein the oxide semiconductor film comprises a c-axis aligned crystalline oxide semiconductor,
wherein the oxide semiconductor film is an In—Ga—Zn-based oxide film, and
wherein the metal oxide film is a Ga—Zn-based oxide film.

7. The display device according to claim 6 , wherein the silicon nitride oxide film has a larger thickness than the silicon oxynitride film.

8. The display device according to claim 6 , wherein the metal oxide film has a smaller thickness than the silicon nitride oxide film.

9. The display device according to claim 6 , wherein the display device comprises a liquid crystal element.

10. The display device according to claim 6 , wherein the display device comprises an organic electroluminescent element.

Assignees

• Nomura Masafumi
• Okazaki Kenichi
• Miyamoto Toshiyuki
• Hamochi Takashi
• Yamazaki Shunpei
• Semiconductor Energy Lab

Inventors

• Nomura Masafumi
• Okazaki Kenichi
• Miyamoto Toshiyuki
• Hamochi Takashi
• Yamazaki Shunpei

Classifications

• H10D30/6756

  Amorphous oxide semiconductors · CPC title

• H10D30/6755

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

• H10D30/6704

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

• H10D30/031

  of thin-film transistors [TFT] · CPC title

• H10D64/68

  characterised by the insulator, e.g. by the gate insulator · CPC title