Electro-optic device and projection-type display apparatus

Patent metadata

Field	Value
Publication number	US-8994904-B2
Application number	US-201113232479-A
Country	US
Kind code	B2
Filing date	Sep 14, 2011
Priority date	Nov 15, 2010
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

An electro-optic device is provided with an substrate, in which a stress relieving film formed of a doped silicon oxide film is formed between a third interlayer insulating film formed of a non-doped silicon oxide film and a pixel electrode formed of an aluminum film or the like. The stress relieving film is formed of the doped silicon oxide film, has a thermal expansion coefficient different from that of the third interlayer insulating film, comes in contact with the third interlayer insulating film, has a thermal expansion coefficient different from that of the pixel electrode, and comes in contact with the pixel electrode. The thermal expansion coefficients are in the following relation of Third Interlayer Insulating Film<Stress relieving Film<Pixel Electrode.

First claim

What is claimed is:

1. An electro-optic device comprising:
a pixel transistor that is provided on one side of a substrate of an element substrate;
an interlayer insulating film that covers the pixel transistor on a side of the pixel transistor opposite to a substrate side of the pixel transistor;
a reflective pixel electrode corresponding to the pixel transistor and being provided on a side of the interlayer insulating film opposite to a substrate side of the interlaying insulating film, the reflective pixel electrode having a thermal expansion coefficient different from that of the interlayer insulating film, the reflective pixel electrode including aluminum;
a transparent insulating film that overlaps with the reflective pixel electrode on a side of the reflective pixel electrode opposite to a substrate side of the reflective pixel electrode; and
an insulating stress relieving film that is provided between the interlayer insulating film and the reflective pixel electrode, a part of the insulating stress relieving film coming in contact with the interlayer insulating film and having a thermal expansion coefficient different from a thermal expansion coefficient of the interlayer insulating film, and a part of the insulating stress relieving film coming in contact with the reflective pixel electrode and having a thermal expansion coefficient different from a thermal expansion coefficient of the reflective pixel electrode,
wherein the reflective pixel electrode has a reflective surface being covered with an alignment film, and
wherein the stress relieving film has a thermal expansion coefficient between the thermal expansion coefficient of the interlayer insulating film and the thermal expansion coefficient of the reflective pixel electrode.

2. The electro-optic device according to claim 1 , wherein a surface layer of the reflective pixel electrode on the transparent insulating film side is formed of an aluminum film.

3. The electro-optic device according to claim 1 , wherein the stress relieving film is a monolayer film having a thermal expansion coefficient larger than the thermal expansion coefficient of the interlayer insulating film and smaller than the thermal expansion coefficient of the reflective pixel electrode.

4. The electro-optic device according to claim 1 , wherein the stress relieving film is provided with a first stress relieving film having a thermal expansion coefficient different from that of the interlayer insulating film and coming in contact with the interlayer insulating film, and a second stress relieving film having a thermal expansion coefficient different from those of the first stress relieving film and the reflective pixel electrode and coming in contact with the first stress relieving film and the reflective pixel electrode.

5. The electro-optic device according to claim 4 , wherein the first stress relieving film has a thermal expansion coefficient larger than that of the interlayer insulating film, and
wherein the second stress relieving film has a thermal expansion coefficient smaller than those of the first stress relieving film and the reflective pixel electrode.

6. The electro-optic device according to claim 1 , wherein at least a part of the insulating film coming in contact with the reflective pixel electrode is formed of a doped silicon oxide film which is doped by at least one of phosphorus and boron.

7. The electro-optic device according to claim 1 , further comprising:
an opposed substrate that is opposed to one side of the element substrate; and
a liquid crystal layer that is kept between the element substrate and the opposed substrate,
wherein the alignment film is provided on the outermost surface of the element substrate.

8. The electro-optic device according to claim 7 , wherein the alignment film is formed of an inorganic alignment film.

9. A projection-type display apparatus provided with the electro-optic device according to claim 7 , comprising:
a light source unit that outputs light supplied to the electro-optic device; and
a projection optical system that projects light modulated by the electro-optic device.

10. The electro-optic device according to claim 1 , wherein the thickness of the insulating stress relieving film is no more than approximately one-tenth of the thickness of the interlayer insulating film.

11. The electro-optic device according to claim 1 , wherein the reflective pixel electrode includes an upper layer formed of an aluminum film and a lower layer formed of a titanium film or a titanium nitride film.

12. An electro-optical device comprising:
a substrate;
a pixel transistor;
an interlayer insulating film, the pixel transistor being disposed between the substrate and the interlayer insulating film;
a pixel electrode that reflects light, the pixel electrode electrically connecting to the pixel transistor, the pixel electrode including aluminum;
an alignment film that covers the pixel electrode; and
an insulating stress relieving film that is disposed between the interlayer insulating film and the pixel electrode,
wherein
the pixel electrode has a reflective surface being covered with the alignment film,
a thermal expansion coefficient of the insulating stress relieving film is larger than a thermal expansion coefficient of the interlayer insulating film, and
the thermal expansion coefficient of the insulating stress relieving film is smaller than a thermal expansion coefficient of the pixel electrode.

13. The electro-optical device according to claim 12 , further comprising:
a relay electrode that electrically connects the pixel transistor and the pixel electrode.

14. The electro-optical device according to claim 13 , further comprising:
a through hole that penetrates the insulating stress relieving film and the interlayer insulating film,
the relay electrode connecting to the pixel electrode via the through hole.

15. The electro-optical device according to claim 12 , wherein:
the insulating stress relieving film contacts the interlayer insulating film and the pixel electrode.

Assignees

• Jiroku Hiroaki
• Seiko Epson Corp

Inventors

• Jiroku Hiroaki

Classifications

• G02F1/136227 Primary

  Through-hole connection of the pixel electrode to the active element through an insulation layer · CPC title

• G02F2201/50

  Protective arrangements · CPC title