ELECTRO-OPTIC DEVICE, METHOD FOR FABRICATING THE SAME, AND ELECTRONIC APPARATUS

Abstract

An electro-optic device includes a substrate, data lines and scanning lines extending so as to cross each other, pixel electrodes each arranged for one of a plurality of pixels defined by crossing of the data lines and the scanning lines in plan view of the substrate, thin film transistors each electrically connected to one of the pixel electrodes, and storage capacitors each electrically connected to one of the pixel electrodes. Each of the storage capacitors is arranged above the corresponding thin film transistor so as to overlap at least a channel region of the thin film transistor in plan view of the substrate. The storage capacitors each include a lower electrode composed of a polysilicon film and an upper electrode composed of a dielectric film and a metal film stacked in this order from the bottom.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a plan view illustrating the entire configuration of a liquid crystal device according to a first embodiment of the invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1.

FIG. 3 is an equivalent circuit diagram illustrating various elements of pixels of a liquid crystal device according to the first embodiment of the invention.

FIG. 4 is a plan view of a plurality of pixels adjacent to each other of a liquid crystal device according to the first embodiment of the invention.

FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4.

FIG. 6 is a partially enlarged cross-sectional view of a portion indicated by VI in FIG. 5.

FIG. 7 is a diagram showing a cross-sectional configuration (1) of the liquid crystal device according to the first embodiment of the inventions in relation to a series of fabrication steps.

FIGS. 8A to 8C are diagrams each showing a cross-sectional configuration (2) of the storage capacitor of the liquid crystal device according to the first embodiment of the invention, in relation to a series of fabrication steps.

FIG. 9 is a diagram showing a cross-sectional configuration (3) of the liquid crystal device according to the first embodiment of the invention, in relation to a series of fabrication steps.

FIG. 10 is a diagram showing a cross-sectional configuration (4) of the liquid crystal device according to the first embodiment of the invention, in relation to a series of fabrication steps.

FIG. 11 is a plan view showing a structure of a projector that is an electronic apparatus applied with an electro-optic device according to the invention.

Claims

1. An electro-optic device comprising: a substrate;data lines and scanning lines extending so as to cross each other;pixel electrodes each arranged for one of a plurality of pixels defined by crossing of the data lines and the scanning lines in plan view of the substrate;thin film transistors each electrically connected to one of the pixel electrodes; andstorage capacitors each electrically connected to one of the pixel electrodes, each of the storage capacitors being arranged above the corresponding thin film transistor so as to overlap at least a channel region of the thin film transistor in plan view of the substrate, each of the storage capacitors including a lower electrode composed of a polysilicon film and an upper electrode composed of a dielectric film and a metal film stacked in this order from the bottom.

2. The electro-optic device according to claim 1, wherein the optical density value of the metal film is higher than 4.

3. The electro-opt-c device according to claim 1, wherein each of the upper electrodes contains a light-shielding metal.

4. The electro-optic device according to claim 3, wherein each of the upper electrodes contains at least one of titanium nitride, titanium, and tungsten as the light-shielding metal.

5. The electro-optic device according to claim 4, wherein each of the upper electrodes has a stacked structure composed of a first light-shielding layer of titanium nitride, a conductive layer of aluminum, and a second light-shielding layer of titanium nitride stacked in this order from the bottom.

6. The electro-optic device according to claim 1, wherein each of the storage capacitors is arranged below the corresponding data line.

7. The electro-optic device according to claim 1, wherein each of the dielectric films contains at least one of silicon nitride, silicon oxide, tantalum oxide, hafnium oxide, and alumina.

8. The electro-optic device according to claim 1, wherein each of the storage capacitors further includes a high-temperature-deposited oxide film on the top surface of the lower electrode.

9. A method for fabricating an electro-optic device that includes a substrate; data lines and scanning lines extending so as to cross each other; pixel electrodes each arranged for one of a plurality of pixels defined by crossing of the data lines and the scanning lines in plan view of the substrate; thin film transistors each electrically connected to one of the pixel electrodes; and storage capacitors each composed of a lower electrode, a dielectric film, and an upper electrode stacked in this order from the bottom thereof and each electrically connected to one of the pixel electrodes, the method comprising the steps of: forming the scanning lines on the substrate;forming each of the thin film transistors at a region corresponding to an intersection of one of the data lines and one of the scanning lines in plan view of the substrate;forming each of the storage capacitors above one of the thin film transistors so as to overlap at least a channel region of the corresponding thin film transistor in plan view of the substrate by stacking a polysilicon film as the lower electrode and a dielectric film and a metal film as the upper electrode in this order from the bottom;forming each of the data lines so as to intersect the scanning lines in plan view of the substrate; andforming each of the pixel electrodes for each pixel so as to be electrically connected to the corresponding storage capacitor.

10. The method for fabricating an electro-optic device according to claim 9, wherein the step of forming the storage capacitors further includes a step of oxidizing a top surface of the lower electrode before forming the dielectric film.

11. The method for fabricating an electro-optic device according to claim 9, wherein the step of forming the storage capacitors further includes a step of firing the dielectric film before stacking the upper electrode.

12. The method for fabricating an electro-optic device according to claim 9, wherein each of the dielectric films is formed by an atomic layer deposition method in the step of forming the storage capacitors.

13. The method for fabricating an electro-optic device according to claim 9, the method further comprising the step of: forming an interlayer insulating film by a low-temperature plasma chemical vapor deposition method on a top surface of each of the upper electrodes for providing electrical insulation between the upper electrode and the data line.

14. An electronic apparatus, the electronic apparatus being provided with the electro-optic device according to claim 1.