Thin-film transistor, display apparatus and electronic apparatus

• US 9,276,122 B2
• Filed: 01/25/2012
• Issued: 03/01/2016
• Est. Priority Date: 02/10/2011
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: JOLED Inc.
• Inventors: Yokozeki, Mikihiro
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): Han, Jonathan
• Application Number:
  US13/358,152
• Publication Number:
  US 20120205648A1
• Time in Patent Office: 1,497 Days
• Field of Search: 257/43, 257/E29.1, 257/E29.273, 257/E29.003
• US Class Current: 1/1
• 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

Disclosed herein is a thin-film transistor having a gate electrode; a source electrode and a drain electrode which form a source/drain-electrode pair; and a channel layer which is provided between the gate electrode and the source/drain-electrode pair, includes a poly-crystal oxide semiconductor material and has a film thickness smaller than the average diameter of crystal grains of the poly-crystal oxide semiconductor material.

Claims

1. A thin-film transistor comprising:

a substrate;

a gate electrode;

a source electrode and a drain electrode which form a source/drain-electrode pair; and

a channel layer between said gate electrode and said source/drain-electrode pair,

wherein,

said channel layer includes a poly-crystal oxide semiconductor material and has a thickness in a range of 10 nm to 20 nm, inclusive, and

the poly-crystal oxide semiconductor material has a (222) face parallel to the substrate.

2. The thin-film transistor according to claim 1 wherein said poly-crystal oxide semiconductor material is an In₂O₃-group oxide semiconductor.

3. The thin-film transistor according to claim 2 wherein, in said channel layer including said In₂O₃-group oxide semiconductor, the (222) face or a (400) face of which matches a carrier propagation direction.

4. The thin-film transistor according to claim 1 wherein the crystal structure of said poly-crystal oxide semiconductor material is the Bixbyite structure.

5. The thin-film transistor according to claim 4 wherein, in said channel layer including said poly-crystal oxide semiconductor adopting said Bixbyite structure, the crystal axis of said crystal grains is oriented in the same direction as the (222) face or a (400) face.

6. The thin-film transistor according to claim 1 wherein said channel layer includes an impurity material.

7. The thin-film transistor according to claim 6 wherein said impurity material is selected from the group consisting of titanium (Ti), aluminum (Al), gallium (Ga), zinc (Zn), tin (Sn), molybdenum (Mo), and a lanthanoid element.

8. A display apparatus comprising:

a display device and

a thin-film transistor for driving said display device,

wherein, said thin-film transistor includes;

a substrate;

a gate electrode;

a source electrode and a drain electrode which form a source/drain-electrode pair;

a channel layer between said gate electrode and said source/drain-electrode pair, said channel layer includes a poly-crystal oxide semiconductor material and has a film thickness in a range of 10 nm to 20 nm, inclusive, and

the poly-crystal oxide semiconductor material has a (222) face parallel to the substrate.

9. An electronic apparatus including a display apparatus, said display apparatus comprising:

a display device and

a thin-film transistor configured to drive said display device,

wherein said thin-film transistor includes;

a substrate,

a gate electrode,

a source electrode and a drain electrode which form a source/drain-electrode pair,

a channel layer between said gate electrode and said source/drain-electrode pair, the channel layer including a poly-crystal oxide semiconductor material and having a thickness in a range of 10 nm to 20 nm, inclusive, and

the poly-crystal oxide semiconductor material has a (222) face parallel to the substrate.