Oxide thin film transistor

• US 8,253,134 B2
• Filed: 03/19/2008
• Issued: 08/28/2012
• Est. Priority Date: 08/29/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sun-il, Lee, Jae-cheol, Song, I-hun, Park, Young-soo, Kim, Chang-jung, Park, Jae-chul
• Primary Examiner(s): Hu, Shouxiang
• Application Number:
  US12/076,486
• Publication Number:
  US 20090057663A1
• Time in Patent Office: 1,623 Days
• Field of Search: 257/43, 257/57, 257/59, 257/E29.08, 257/E29.101
• US Class Current: 257/43
• 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 21/02581 Transition metal or rare earth elements
• 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

An oxide thin film transistor and a method of manufacturing the oxide TFT are provided. The oxide thin film transistor (TFT) including: a gate; a channel formed to correspond to the gate, and a capping layer having a higher work function than the channel; a gate insulator disposed between the gate and the channel; and a source and drain respectively contacting either side of the capping layer and the channel and partially on a top surface of the capping layer.

Claims

1. An oxide thin film transistor (TFT) comprising:

a gate;

a channel on the gate;

a capping layer on the channel, the capping layer having a higher work function than the channel, the capping layer and the channel having substantially the same width;

a gate insulator between the gate and the channel; and

a source and drain each partially covering a top surface of the capping layer and each covering sides of the capping layer and sides of the channel, wherein the capping layer includes an oxide not included in the channel.

2. The oxide TFT of claim 1, wherein the channel is formed of a material of In—

Zn oxide doped with Ni.

3. The oxide TFT of claim 1, wherein the channel is formed of a material of Ni—

In—

Zn oxide doped with a first, a second, or a third group transition element.

4. The oxide TFT of claim 3, wherein the first group transition element may be Cu, Ag, or Au, the second group transition element may be Pd, Pt, or Ds, and the third group transition element may be Co, Ir, or Mt.

5. The oxide TFT of claim 2, wherein the capping layer is Ga—

In—

Zn oxide.

6. The oxide TFT of claim 2, wherein the capping layer is Ga—

In—

Zn oxide doped with at least one of Cu, Ag, Au, Pd, Pt, and DS.