Semiconductor device and manufacturing method of the same

Patent metadata

Field	Value
Publication number	US-10468531-B2
Application number	US-201615293434-A
Country	US
Kind code	B2
Filing date	Oct 14, 2016
Priority date	May 20, 2010
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

One object is to provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and high reliability. Another object is to manufacture a highly reliable semiconductor device in a high yield. In a top-gate staggered transistor including an oxide semiconductor film, as a first gate insulating film in contact with the oxide semiconductor film, a silicon oxide film is formed by a plasma CVD method with use of a deposition gas containing silicon fluoride and oxygen; and as a second gate insulating film stacked over the first gate insulating film, a silicon oxide film is formed by a plasma CVD method with use of a deposition gas containing silicon hydride and oxygen.

First claim

The invention claimed is:

1. A semiconductor device comprising:
an insulating film;
a source electrode layer and a drain electrode layer over the insulating film;
an island-shaped oxide semiconductor film over the insulating film, the source electrode layer, and the drain electrode layer;
an island-shaped first gate insulating film over and in contact with the island-shaped oxide semiconductor film;
a second gate insulating film over the insulating film, the source electrode layer, the drain electrode layer, the island-shaped oxide semiconductor film, and the island-shaped first gate insulating film; and
a gate electrode layer over the second gate insulating film,
wherein the island-shaped first gate insulating film includes a silicon oxide film containing fluorine,
wherein the second gate insulating film contains hydrogen,
wherein a hydrogen concentration of the second gate insulating film is higher than a hydrogen concentration of the island-shaped first gate insulating film, and
wherein a width of the island-shaped oxide semiconductor film is smaller than a width of the gate electrode layer in a direction perpendicular to a direction from the source electrode layer to the drain electrode layer.

2. The semiconductor device according to claim 1 , wherein a thickness of the island-shaped first gate insulating film is smaller than a thickness of the second gate insulating film.

3. The semiconductor device according to claim 1 , wherein a thickness of the island-shaped first gate insulating film is greater than or equal to 1 nm and less than or equal to 10 nm.

4. The semiconductor device according to claim 1 ,
wherein a hydrogen concentration in the island-shaped first gate insulating film is lower than a fluorine concentration in the island-shaped first gate insulating film,
wherein the fluorine concentration is greater than or equal to 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration is less than 1×10 20 atoms/cm 3 .

5. The semiconductor device according to claim 1 ,
wherein a hydrogen concentration in the second gate insulating film is higher than a fluorine concentration in the second gate insulating film,
wherein the fluorine concentration is less than 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration is greater than or equal to 1×10 20 atoms/cm 3 .

6. A semiconductor device comprising:
an insulating film;
a source electrode layer and a drain electrode layer over the insulating film;
an island-shaped oxide semiconductor film over the insulating film, the source electrode layer, and the drain electrode layer;
an island-shaped first gate insulating film over and in contact with the island-shaped oxide semiconductor film;
a second gate insulating film over the insulating film, the source electrode layer, the drain electrode layer, the island-shaped oxide semiconductor film, and the island-shaped first gate insulating film; and
a gate electrode layer over the second gate insulating film,
wherein the island-shaped first gate insulating film includes a silicon oxide film containing fluorine,
wherein the second gate insulating film contains hydrogen,
wherein a hydrogen concentration of the second gate insulating film is higher than a hydrogen concentration of the island-shaped first gate insulating film,
wherein the insulating film includes a silicon oxide film containing fluorine, and
wherein a width of the island-shaped oxide semiconductor film is smaller than a width of the gate electrode layer in a direction perpendicular to a direction from the source electrode layer to the drain electrode layer.

7. The semiconductor device according to claim 6 , wherein a thickness of the island-shaped first gate insulating film is smaller than a thickness of the second gate insulating film.

8. The semiconductor device according to claim 6 , wherein a thickness of the island-shaped first gate insulating film is greater than or equal to 1 nm and less than or equal to 10 nm.

9. The semiconductor device according to claim 6 ,
wherein a hydrogen concentration in the island-shaped first gate insulating film is lower than a fluorine concentration in the island-shaped first gate insulating film,
wherein the fluorine concentration is greater than or equal to 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration is less than 1×10 20 atoms/cm 3 .

10. The semiconductor device according to claim 6 ,
wherein a hydrogen concentration in the second gate insulating film is higher than a fluorine concentration in the second gate insulating film,
wherein the fluorine concentration is less than 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration is greater than or equal to 1×10 20 atoms/cm 3 .

11. A semiconductor device comprising:
an insulating film;
a source electrode layer and a drain electrode layer over the insulating film;
an island-shaped oxide semiconductor film over the insulating film, the island-shaped oxide semiconductor film electrically connected to the source electrode layer and the drain electrode layer;
a first gate insulating film in contact with the island-shaped oxide semiconductor film;
a second gate insulating film in contact with the first gate insulating film; and
a gate electrode layer, wherein the gate electrode layer and the island-shaped oxide semiconductor film overlap with each other,
wherein the first gate insulating film includes a silicon oxide film containing fluorine,
wherein the second gate insulating film contains hydrogen and fluorine,
wherein a hydrogen concentration of the second gate insulating film is higher than a hydrogen concentration of the first gate insulating film, and
wherein a width of the island-shaped oxide semiconductor film is smaller than a width of the gate electrode layer in a direction perpendicular to a direction from the source electrode layer to the drain electrode layer.

12. The semiconductor device according to claim 11 , wherein the first gate insulating film is island-shaped.

13. The semiconductor device according to claim 11 , wherein a thickness of the first gate insulating film is smaller than a thickness of the second gate insulating film.

14. The semiconductor device according to claim 11 , wherein a thickness of the first gate insulating film is greater than or equal to 1 nm and less than or equal to 10 nm.

15. The semiconductor device according to claim 11 ,
wherein the hydrogen concentration of the first gate insulating film is lower than a fluorine concentration of the first gate insulating film,
wherein the fluorine concentration of the first gate insulating film is greater than or equal to 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration of the first gate insulating film is less than 1×10 20 atoms/cm 3 .

16. The semiconductor device according to claim 11 ,
wherein the hydrogen concentration of the second gate insulating film is higher than a fluorine concentration of the second gate insulating film,
wherein the fluorine concentration of the second gate insulating film is less than 1×10 20 atoms/cm 3 , and
wherein the hydrogen concentration of the second gate insulating film is greater than or equal to 1×10 20 atoms/cm 3 .

Assignees

• Semiconductor Energy Lab

Inventors

• Kimura Kunio
• Ichijo Mitsuhiro
• Endo Toshiya

Classifications

• H10P95/94

  Hydrogenation or deuterisation, e.g. using atomic hydrogen from a plasma · CPC title

• G02F1/133345

  Insulating layers (G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence) · CPC title

• G02F1/13394

  spacers regularly patterned on the cell subtrate, e.g. walls, pillars (G02F1/133377 takes precedence) · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/134309

  characterised by their geometrical arrangement · CPC title