Thin-film transistor and method for forming the same

• US 9,865,745 B2
• Filed: 02/01/2016
• Issued: 01/09/2018
• Est. Priority Date: 07/03/2015
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Lin, Liang-Yu, Cheng, Chun-Cheng
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): Han, Jonathan
• Application Number:
  US15/011,794
• Publication Number:
  US 20170005199A1
• Time in Patent Office: 708 Days
• Field of Search: 257E27111, 257E21414, 257E29151, 438 99, 438149, 438151, 15E27111, 15E21414, 15E29151
• 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 21/02628 using solutions
• 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 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 29/242 AIBVI or AIBVII compounds, e.g. Cu2O, Cu I H01L29/247 takes precedence
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A thin-film transistor comprises a substrate, a first electrode on the top surface of the substrate, an insulation layer on the top surface of the substrate and covering the first electrode, a semiconductor oxide layer on the top surface of the insulation layer, a protection layer on the top surface of the semiconductor oxide layer, an organic dielectric layer on the top surface of the semiconductor oxide layer and covering the protection layer, a source electrode and a drain electrode both penetrating the organic dielectric layer from the top surface thereof. A channel thickness of the semiconductor oxide layer is not thicker than 20 nanometers. The source electrode contacts the semiconductor oxide layer at the first side of the protection layer and the drain electrode contacts the semiconductor oxide layer at the second side, opposite to the first side, of the protection layer.

Claims

1. A thin-film transistor, comprising:

a substrate;

a gate electrode disposed on a top surface of the substrate;

a gate insulator layer disposed on the top surface of the substrate and covering on the gate electrode;

a semiconductor oxide layer disposed on the top surface of the gate insulator layer and comprising a semiconductor channel, and a thickness of the semiconductor oxide layer not being larger than 20 nanometers(nm);

a protection layer disposed on a top surface of the semiconductor oxide layer and corresponding to the semiconductor channel;

an organic dielectric layer disposed over both the protection layer and the semiconductor oxide layer, the organic dielectric layer being in contact with a top surface of the protection layer, the organic dielectric layer also being in contact with the top surface of the semiconductor oxide layer on lateral sides of the semiconductor oxide layer, which are not covered by the protection layer, and comprising a plurality of through holes; and

a source electrode and a drain electrode, disposed on a top surface of the organic dielectric layer and contacting the semiconductor oxide layer through the plurality of through holes.

2. The thin-film transistor according to claim 1, wherein the semiconductor oxide layer is made of metallic oxide, and the metallic oxide is selected from at least one of a group consisting of indium gallium zinc oxide, gallium oxide, indium oxide, zinc oxide, indium tin oxide and a combination thereof.

3. The thin-film transistor according to claim 1, wherein the protection layer is made of an inorganic isolation material, and the inorganic isolation material is selected from at least one of a group consist of silicon nitride, silicon dioxide, silicon oxynitride, metallic oxide, and a combination thereof.

4. The thin-film transistor according to claim 1, wherein the organic dielectric layer is made of at least one of a group consisting of organic polymer, organic photoresist and organic-inorganic hybrid material.

5. The thin-film transistor according to claim 4, wherein the organic dielectric layer is made of an organic compound with a functional group, and the functional group is selected from a group consisting of hydroxyl, amino and mercaptan.

6. The thin-film transistor according to claim 1, wherein the protection layer partially covers the top surface of the semiconductor oxide layer, and a bottom surface of the protection layer is substantially smaller than the top surface of the semiconductor oxide layer.

7. The thin-film transistor according to claim 6, wherein an area of the protection layer is substantially the same as an area of the semiconductor channel.