Electro-optical device and electronic apparatus having the same

• US 7,742,017 B2
• Filed: 05/22/2006
• Issued: 06/22/2010
• Est. Priority Date: 05/26/2005
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yamasaki, Ryosuke
• Primary Examiner(s): Tran; Henry N
• Assistant Examiner(s): Leiby; Christopher E
• Application Number:
  US11/438,561
• Publication Number:
  US 20060270083A1
• Time in Patent Office: 1,492 Days
• Field of Search: 345/55, 361/312, 438/29, 438/396, 257/98
• US Class Current: 345/55
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

An electro-optical device includes a holding capacitor with a first electrode electrically connected to a transistor and a pixel electrode, a second electrode disposed opposite to the first electrode, and a multilayer dielectric film structure disposed between the first electrode and the second electrode. The multilayer dielectric film structure includes a low dielectric film and first and second high dielectric films. The first and second high dielectric films sandwich the low dielectric film from a first electrode side and a second electrode side, respectively. Both of the first and second high dielectric films have a permittivity that is higher than that of the low dielectric film.

Claims

1. An electro-optical device, comprising:

a data line and a scanning line that intersect each other;

a transistor supplied with a scanning signal by the scanning line;

a pixel electrode supplied, through the transistor, with an image signal from the data line; and

a holding capacitor including a first electrode electrically connected to the transistor and the pixel electrode, a second electrode disposed opposite to the first electrode and electrically connected to a capacitor wiring, and a multilayer dielectric film structure including;

a low dielectric film consisting of a high temperature oxide film;

a first high dielectric film disposed between the first electrode and the low dielectric film, the first high dielectric film consisting of a silicon nitride film; and

a second high dielectric film disposed between the low dielectric film and the second electrode, the second high dielectric film consisting of a silicon nitride film, the first high dielectric film and the second high dielectric film having a permittivity relatively higher than a permittivity of the low dielectric film, the second high dielectric film having a thicker film thickness than the first high dielectric film;

wherein the holding capacitor is disposed above a semiconductor layer of the transistor; and

wherein stack-layer positions of the first high dielectric film and the second high dielectric film in the direction toward the first electrode and the second electrode, respectively, are symmetrical with respect to the low dielectric film; and

wherein the multilayer structure is formed by stacking silicon nitride films of the same number on both sides of the high temperature oxide film.

2. The electro-optical device according to claim 1, wherein the second electrode is held at a reference voltage potential;

wherein the second high dielectric film is electrically connected to the second electrode; and

wherein a voltage with a voltage different from the reference voltage potential is sequentially applied to the pixel electrode via the first electrode.

3. The electro-optical device according to claim 2, wherein the second high dielectric film is formed on the second electrode.

4. The electro-optical device according to claim 1,

wherein the plurality of pixel electrodes are arranged on the substrate in a matrix;

and

wherein different polarity voltages are applied to;

different pixel lines of the plurality of pixel electrodes arranged in the matrix,

different pixel rows of the plurality of pixel electrodes arranged in the matrix,

different pixel electrodes adjacent in both a row and line directions, or

different groups controlled as different fields.