THIN-FILM TRANSISTOR

• US 20130112972A1
• Filed: 01/02/2013
• Published: 05/09/2013
• Est. Priority Date: 07/02/2010
• Status: Active Grant

• Current Assignee: Advanced Interconnect Materials, LLC
• Original Assignee: Advanced Interconnect Materials, LLC
• Inventors: KOIKE, Junichi, KAWAKAMI, Hideaki, YUN, Pilsang
• Granted Patent: US 8,866,140 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

Making it possible to improve adhesion between the semiconductor layer and the electrodes, realize high-speed operation of the thin-film transistor by enhancing ohmic contact between these members, reliably prevent oxidation of the electrode surfaces, and realize an electrode fabrication process with few processing steps. The thin-film transistor 10 of the present invention includes a semiconductor layer 4 composed of oxide semiconductor, a source electrode 5 and a drain electrode 6 that are layers composed mainly of copper, and oxide reaction layers 22 provided between the semiconductor layer 4 and each of the source electrode 5 and drain electrode 6, and high-conductance layers 21 provided between the oxide reaction layers 22 and semiconductor layer 4.

Claims

1. A thin-film transistor characterized by comprising:

a semiconductor layer composed of oxide semiconductor;

a source electrode and a drain electrode that are layers composed mainly of copper; and

oxide reaction layers formed between the semiconductor layer and, respectively, the source electrode and the drain electrode.

2. The thin-film transistor as recited in claim 1, wherein the semiconductor layer has low-resistance ohmic contact through the oxide reaction layers to the source electrode and the drain electrode.

3. The thin-film transistor recited in claim 1, comprising high-conductance layers between the oxide reaction layers and the semiconductor layer.

4. The thin-film transistor recited in claim 3, wherein the semiconductor layer has low-resistance ohmic contact through the oxide reaction layers and the high-conductance layers to the source electrode and the drain electrode.

5. The thin-film transistor as recited in claim 1, wherein the semiconductor layer is amorphous In—

Ga—

Zn—

O_x.

6. The thin-film transistor as recited in claim 5, wherein the high-conductance layers are rich in In concentration.

7. The thin-film transistor as recited in claim 1, wherein the source electrode and drain electrode are composed of Cu—

Mn alloy.

8. The thin-film transistor as recited in claim 1, wherein the oxide reaction layers are composed mainly of MnO_x.

9. The thin-film transistor as recited in claim 8, wherein the oxide reaction layers contain Cu, In, Ga and Zn.

10. The thin-film transistor as recited in claim 1, wherein the oxide reaction layers are formed in contact with the Cu—

Mn alloy forming surface layers of the source electrode and the drain electrode.

11. The thin-film transistor recited in claim 2, comprising high-conductance layers between the oxide reaction layers and the semiconductor layer.

12. The thin-film transistor recited in claim 11, wherein the semiconductor layer has low-resistance ohmic contact through the oxide reaction layers and the high-conductance layers to the source electrode and the drain electrode.