Active matrix assembly with light blocking layer over channel region

• US 6,316,790 B1
• Filed: 05/20/1997
• Issued: 11/13/2001
• Est. Priority Date: 04/30/1982
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Oshima, Hiroyuki, Mano, Toshihiko, Kodaira, Toshimoto
• Primary Examiner(s): JACKSON JR, JEROME
• Application Number:
  US08/859,494
• Time in Patent Office: 1,638 Days
• Field of Search: 257/59, 257/72, 257/448
• US Class Current: 257/72
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: H01L 23/53209 based on metals, e.g. alloys, metal silicides H01L23/53285 takes precedence
• CPC Class Codes: H01L 23/5386 Geometry or layout of the interconnection structure
• 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
• CPC Class Codes: H01L 29/41725 Source or drain electrodes for field effect devices with monocrystalline semiconductor on source/drain region H01L29/0843
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Improved thin film transistors resistant to photo-induced current and having improved electrical contact between electrodes and the source or drain regions are provided. The thin film transistors formed in accordance with the invention are particularly well suited for use in an active matrix substrate for a liquid crystal display panel. The liquid crystal display panels include an additional insulating layer formed between crossing orthogonal source lines and gate lines to provide a higher breakdown voltage between the source lines and gate lines than at the gate insulating layer of the thin film transistors.

Claims

1. An active matrix assembly comprising:

a transmissive electro-optical device including a plurality of liquid crystal cells, data signals being supplied to the plurality of liquid crystal cells through a plurality of field effect transistors, each of the plurality of field effect transistors comprising;

a channel region, a source region and a drain region, the channel region comprising a non-monocrystalline silicon layer over an insulating transparent

a gate insulating film in contact with at least the channel region;

a gate electrode in contact with the gate insulating film; and

a non-transparent electrode connected to the drain region, the non-transparent electrode completely overlapping the channel region.

2. The active matrix assembly of claim 1, wherein the non-transparent electrode is aluminum.

3. The active matrix assembly of claim 1, wherein the non-monocrystalline silicon layer is a polycrystalline silicon layer.

4. The active matrix assembly of claim 3, wherein the polycrystalline silicon layer has a thickness less than 2500 A.