Active matrix substrate

• US 5,614,730 A
• Filed: 11/08/1991
• Issued: 03/25/1997
• Est. Priority Date: 11/09/1990
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nakazawa, Takashi, Ishiguro, Hideto
• Primary Examiner(s): LOKE, STEVEN HO YIN
• Application Number:
  US07/790,253
• Time in Patent Office: 1,964 Days
• Field of Search: 357/2, 357/4, 357/23.7, 357/54, 359/54, 359/59, 359/61, 257/57, 257/59, 257/66, 257/72, 257/347, 257/350, 257/352
• US Class Current: 257/59
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body

Abstract

There is disclosed an active matrix substrate including on a given substrate a thin film transistor, a scanning line connected to the gate of the thin film transistor, a data bus connected to the source of the thin film transistor, and a picture element electrode connected to the data bus through the thin film transistor, the active matrix substrate comprising a structure of the scanning line having the surface covered with an insulating film. A semiconductor layer covered with a gate insulating film constituting the thin film transistor, and a gate electrode constituting the thin film transistor, which are laid on each other in the stated order.

Claims

1. A liquid crystal device, comprising:

a pair of opposed and spaced apart insulating substrates;

a plurality of scanning lines and a plurality of data lines disposed on one of the substrates, the scanning lines intersecting the data lines at cross-over locations;

a plurality of switching elements connected to the scanning lines and the data lines;

pixel electrodes arranged on the one of the substrates, each of the pixel electrodes being electrically connected to respective ones of the switching elements and being extended so as to overlap one of the scanning lines connected to an adjacent one of the switching elements;

a plurality of first layers located between each of the scanning lines and each of the data lines at the cross-over locations, said plurality of first layers including a first electrically conductive film, a tantalum oxide film and an electrically insulating film; and

a plurality of second layers located between each of the pixel electrodes and each of the scanning lines, the plurality of second layers including a plurality of electrically insulating films and a second electrically conductive film.

2. A liquid crystal device, comprising:

a pair of opposed and spaced apart insulating substrates;

a plurality of scanning lines and a plurality of data lines disposed on one of the substrates, the scanning lines intersecting the data lines at cross-over locations;

a plurality of switching elements connected to the scanning lines and the data lines;

pixel electrodes arranged on the one of the substrates, each of the pixel electrodes being electrically connected to respective ones of the switching elements and being extended so as to overlap one of the scanning lines connected to an adjacent one of the switching elements;

a plurality of first layers located between each of the scanning lines and each of the data lines at the cross-over locations, said plurality of first layers including a first electrically conductive film, a silicon oxide film and a tantalum oxide film; and

a plurality of second layers located between each of the pixel electrodes and each of the scanning lines, the plurality of second layers including a plurality of electrically insulating films and a second electrically conductive film.

3. The liquid crystal device of claim 2, wherein the switching elements comprise thin film transistors including gate electrodes electrically connected to the scanning lines, wherein each of the gate electrodes is made of a same material as the first and second electrically conductive films.

4. The liquid crystal device of claim 2, wherein the switching elements comprise thin film transistors including gate electrodes, said gate electrodes are connected to the scanning lines through gate wirings, and the scanning lines are made of a material different than the gate electrodes, the scanning lines being made of a material selected from the group consisting of Cr, Ta, and ITO and the gate electrodes being made of a material selected from the group consisting of Cr, and Mo.

5. A liquid crystal device, comprising:

a pair of opposed and spaced apart insulating substrates;

a plurality of scanning lines and a plurality of data lines disposed on one of the substrates, the scanning lines intersecting the data lines at cross-over locations;

a plurality of switching elements connected to the scanning lines and the data lines;

pixel electrodes arranged on the one of the substrates, each of the pixel electrodes being electrically connected to respective ones of the switching elements and being extended so as to overlap one of the scanning lines connected to an adjacent one of the switching elements;

a plurality of first layers located between each of the scanning lines and each of the pixel electrodes, said plurality of first layers including a first conductive film and a first plurality of electrically insulating films; and

a plurality of second layers located between each of the scanning lines and each of the data lines at the cross-over locations, said plurality of second layers including a electrically conductive layer and a second plurality of electrically insulating films, one of the second plurality of electrically insulating films being a light shielding layer and being provided so as to overlap the pixel electrode.

6. The liquid crystal device of claim 5, wherein the switching elements comprise thin film transistors including gate electrodes electrically connected to the scanning lines, wherein the gate electrodes are made of a same material as the electrically conductive layer.

7. The liquid crystal device of claim 5, wherein the switching elements comprise thin film transistors including gate electrodes, said gate electrodes are connected to the scanning lines through gate wirings, and the scanning lines are made of a material different than the gate electrodes, the material from which the scanning lines are made being selected from the group consisting of Cr, Ta, and ITO and the gate electrodes being made of a material selected from the group consisting of Cr, and Mo.