Thin film transistor substrate and method for manufacturing the same

• US 9,543,329 B2
• Filed: 06/30/2015
• Issued: 01/10/2017
• Est. Priority Date: 07/07/2014
• Status: Active Grant

• Current Assignee: Trivale Technologies, LLC (Vector Capital Corporation)
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Oda, Koji, Inoue, Kazunori, Tsumura, Naoki
• Primary Examiner(s): Erdem, Fazli
• Application Number:
  US14/755,984
• Publication Number:
  US 20160005770A1
• Time in Patent Office: 560 Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/441 Deposition of conductive or insulating materials for electrodes
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A thin film transistor substrate includes: a gate insulating film that covers a gate electrode and a common electrode; a transparent oxide film selectively disposed on the gate insulating film; a source electrode and a drain electrode that are spaced from each other on the transparent oxide film; and a light transmissive pixel electrode electrically connected to the drain electrode. The transparent oxide film includes a conductive region and a semiconductor region. The conductive region is disposed in a lower portion of the source electrode and the drain electrode and disposed in a portion that continues from the lower portion of the drain electrode, extends to part of an upper portion of the common electrode, and forms the pixel electrode. The semiconductor region is disposed in a portion corresponding to a lower layer in a region between the source electrode and the drain electrode.

Claims

1. A thin film transistor substrate including a plurality of pixels arranged in matrix, wherein

each of said pixels includes:

a gate electrode and a common electrode selectively disposed on a substrate;

a gate insulating film that covers said gate electrode and said common electrode;

a transparent oxide film selectively disposed on said gate insulating film;

a source electrode and a drain electrode that are spaced from each other on said transparent oxide film and overlap said gate electrode; and

a light transmissive pixel electrode electrically connected to said drain electrode,

said transparent oxide film including a conductive region and a semiconductor region,

said conductive region being disposed in a lower portion of said source electrode and said drain electrode and disposed in a portion that continues from the lower portion of said drain electrode, extends to part of an upper portion of said common electrode, and forms said pixel electrode, thereby forming said pixel electrode,

said semiconductor region being disposed in a portion that corresponds to a lower layer in a region between said source electrode and said drain electrode and forming a channel region of a thin film transistor,

said source electrode and said drain electrode being electrically connected to said conductive region of said transparent oxide film.

2. The thin film transistor substrate according to claim 1, wherein said conductive region of said transparent oxide film is also disposed in a lower portion of a source wiring extending from said source electrode.

3. A thin film transistor substrate including a plurality of pixels arranged in matrix, wherein

each of said pixels includes:

a gate electrode and a common electrode selectively disposed on a substrate;

a gate insulating film that covers said gate electrode and said common electrode;

a transparent oxide film selectively disposed on said gate insulating film;

a source electrode and a drain electrode that are spaced from each other on said transparent oxide film and overlap said gate electrode;

a light transmissive pixel electrode electrically connected to said drain electrode;

a protective insulating film that covers said source electrode, said drain electrode, and said pixel electrode; and

a counter electrode disposed on said protective insulating film opposite to said pixel electrode,

said counter electrode being electrically connected to said common electrode through a contact hole that penetrates said protective insulating film and said gate insulating film,

said transparent oxide film including a conductive region and a semiconductor region,

said conductive region being disposed in a lower portion of said source electrode and said drain electrode and disposed in a portion that continues from the lower portion of said drain electrode and forms said pixel electrode, thereby forming said pixel electrode,

said semiconductor region being disposed in a portion that corresponds to a lower layer in a region between said source electrode and said drain electrode and forming a channel region of a thin film transistor,

said source electrode and said drain electrode being electrically connected to said conductive region of said transparent oxide film.

4. The thin film transistor substrate according to claim 3, wherein said conductive region of said transparent oxide film is also disposed in a lower portion of a source wiring extending from said source electrode.

5. A thin film transistor substrate including a plurality of pixels arranged in matrix, wherein

each of said pixels includes:

a gate electrode and a common electrode selectively disposed on a substrate;

a gate insulating film that covers said gate electrode and said common electrode;

a transparent oxide film selectively disposed on said gate insulating film;

an n-type Si film that is selectively disposed on said transparent oxide film and contains an n-type impurity;

a source electrode and a drain electrode that are spaced from each other over said transparent oxide film through said n-type Si film and overlap said gate electrode; and

a light transmissive pixel electrode electrically connected to said drain electrode,

said transparent oxide film including a conductive region and a semiconductor region,

said conductive region being disposed below said source electrode and said drain electrode and disposed in a portion that continues from the lower portion of said drain electrode, extends to part of an upper portion of said common electrode, and forms said pixel electrode, thereby forming said pixel electrode,

said semiconductor region being disposed in a portion that corresponds to a lower layer in a region between said source electrode and said drain electrode and forming a channel region of a thin film transistor,

said source electrode and said drain electrode being electrically connected to said conductive region of said transparent oxide film through said n-type Si film.

6. The thin film transistor substrate according to claim 5, wherein

said conductive region of said transparent oxide film is also disposed below a source wiring extending from said source electrode, and

said n-type Si film is also disposed on said conductive region of said transparent oxide film below said source wiring.

7. A thin film transistor substrate including a plurality of pixels arranged in matrix, wherein

each of said pixels includes:

a gate electrode and a common electrode selectively disposed on a substrate;

a gate insulating film that covers said gate electrode and said common electrode;

a transparent oxide film selectively disposed on said gate insulating film;

an n-type Si film that is selectively disposed on said transparent oxide film and contains an n-type impurity;

a source electrode and a drain electrode that are spaced from each other over said transparent oxide film through said n-type Si film and overlap said gate electrode;

a light transmissive pixel electrode electrically connected to said drain electrode;

a protective insulating film that covers said source electrode, said drain electrode, and said pixel electrode; and

a counter electrode disposed on said protective insulating film opposite to said pixel electrode,

said counter electrode being electrically connected to said common electrode through a contact hole that penetrates said protective insulating film and said gate insulating film,

said transparent oxide film including a conductive region and a semiconductor region,

said conductive region being disposed below said source electrode and said drain electrode and disposed in a portion that continues from the lower portion of said drain electrode and forms said pixel electrode, thereby forming said pixel electrode,

said semiconductor region being disposed in a portion that corresponds to a lower layer in a region between said source electrode and said drain electrode and forming a channel region of a thin film transistor,

said source electrode and said drain electrode being electrically connected to said conductive region of said transparent oxide film through said n-type Si film.

8. The thin film transistor substrate according to claim 7, wherein

said conductive region of said transparent oxide film is also disposed below a source wiring extending from said source electrode, and

said n-type Si film is also disposed on said conductive region of said transparent oxide film below said source wiring.