THIN-FILM TRANSISTOR AND METHOD FOR PRODUCING THE SAME

• US 20100320453A1
• Filed: 06/09/2010
• Published: 12/23/2010
• Est. Priority Date: 06/22/2009
• Status: Abandoned Application

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Chen, Haijing, Tanaka, Masanobu, Kurihara, Kenichi, Ishihara, Hirotsugu
• Application Number:
  US12/797,053
• Publication Number:
  US 20100320453A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/484 characterised by the channel regions
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing
• CPC Class Codes: H10K 71/233 by photolithographic etching

Abstract

A thin-film transistor includes a gate electrode disposed on a substrate, a semiconductor layer formed of an organic semiconductor and constituting a channel region, a gate insulating film disposed between the gate electrode and the semiconductor layer, and a pair of source/drain electrodes electrically connected to the semiconductor layer. The semiconductor layer includes a protruding portion protruding toward the substrate from an inner region of a surface, opposite the substrate, of the semiconductor layer excluding a region near ends thereof.

Claims

1. A thin-film transistor comprising:

a gate electrode disposed on a substrate;

a semiconductor layer formed of an organic semiconductor and constituting a channel region, the semiconductor layer including a protruding portion protruding toward the substrate from an inner region of a surface, opposite the substrate, of the semiconductor layer excluding a region near ends thereof;

a gate insulating film disposed between the gate electrode and the semiconductor layer; and

a pair of source/drain electrodes electrically connected to the semiconductor layer;

2. The thin-film transistor according to claim 1, wherein the gate electrode, the gate insulating film, and the semiconductor layer are disposed in order from the substrate, a recess being provided in a region of the gate insulating film opposite the semiconductor layer such that the protruding portion is disposed in the recess.

3. The thin-film transistor according to claim 1, further comprising a buffer layer, wherein the buffer layer, the semiconductor layer, the gate insulating film, and the gate electrode are disposed in order from the substrate, a recess being provided in a region of the buffer layer opposite the semiconductor layer such that the protruding portion is disposed in the recess.

4. The thin-film transistor according to claim 2 or 3, wherein the semiconductor layer includes a channel layer of an organic semiconductor and a contact layer disposed thereon, the pair of source/drain electrodes being in contact with the contact layer.

5. A method for producing a thin-film transistor, comprising the steps of:

forming a gate electrode and a gate insulating film on a substrate in the stated order;

forming a lyophobic layer on the gate insulating film, forming a first opening in the lyophobic layer, and forming a recess having the same size as the first opening in the gate insulating film;

forming a second opening in the lyophobic layer by widening the first opening;

forming a semiconductor layer of a liquid organic semiconductor in the recess of the gate insulating film and the second opening of the lyophobic layer;

drying the semiconductor layer and removing the lyophobic layer; and

forming a pair of source/drain electrodes in contact with the semiconductor layer.

7. The method for producing a thin-film transistor according to claim 5 or 6, wherein the second opening formed in the lyophobic layer is at least 1 μ

m wider than the first opening.

8. The method for producing a thin-film transistor according to claim 5 or 6, wherein the lyophobic layer is formed of a fluoropolymer capable of being applied.

6. A method for producing a thin-film transistor, comprising the steps of:

forming a buffer layer of an insulating material on a substrate;

forming a lyophobic layer on the buffer layer, forming a first opening in the lyophobic layer, and forming a recess having the same size as the first opening in the buffer layer;

forming a second opening in the lyophobic layer by widening the first opening;

forming a semiconductor layer of a liquid organic semiconductor in the recess of the buffer layer and the second opening of the lyophobic layer;

drying the semiconductor layer and removing the lyophobic layer;

forming a gate insulating film on the buffer layer and the semiconductor layer; and

forming a pair of through-holes reaching the semiconductor layer in the gate insulating film and forming a pair of source/drain electrodes in contact with the semiconductor layer via the through-holes.