Method of manufacturing ZnO-based this film transistor

• US 20080318368A1
• Filed: 05/22/2008
• Published: 12/25/2008
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Son, Kyung-seok, Ryu, Myung-kwan, Lee, Sang-yoon, Jung, Ji-sim, Kim, Tae-sang, Park, Kyung-bae, Kwon, Jang-yeon, Lee, Je-hun
• Granted Patent: US 7,682,882 B2
• Time in Patent Office: Days
• US Class Current: 438/151
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

Provided is a method of manufacturing a ZnO-based thin film transistor (TFT). The method may include forming source and drain electrodes using one or two wet etchings. A tin (Sn) oxide, a fluoride, or a chloride having relatively stable bonding energy against plasma may be included in a channel layer. Because the source and drain electrodes are formed by wet etching, damage to the channel layer and an oxygen vacancy may be prevented or reduced. Because the material having higher bonding energy is distributed in the channel layer, damage to the channel layer occurring when a passivation layer is formed may be prevented or reduced.

Claims

1. A method of manufacturing a ZnO-based thin film transistor (TFT), the method comprising:

forming a ZnO-based channel layer on a gate insulating layer;

forming a conductive material layer on the gate insulating layer and the channel layer;

forming a mask layer on the conductive material layer having a pattern corresponding to source and drain electrodes on both sides of the channel layer;

forming the source and drain electrodes by etching a portion of the conductive material layer not covered by the mask layer using a wet etchant having a higher selectivity with respect to the conductive material layer than the channel layer; and

forming a passivation layer covering the source and drain electrodes and the channel layer.

2. The method of claim 1, wherein at least one of a tin (Sn) oxide, a fluoride, and a chloride is included in the channel layer.

3. The method of claim 1, wherein the channel layer is formed of gallium-indium-zinc-oxide (GIZO).

4. The method of claim 2, wherein the channel layer is formed of GIZO.

5. The method of claim 1, wherein the source and drain electrodes are formed by two etchings.

6. The method of claim 5, wherein the two etchings include:

a first etchant having a phosphoric acid, a nitric acid, and an acetic acid as main components; and

a second etchant having water and a hydrogen peroxide as main components and a trace of hydrogen fluoride (HF).

7. The method of claim 6, wherein each of the source and drain electrodes is formed of at least one selected from the group consisting of Cu, Mo, Al, Mo/Cu, Mo/Al, Mo/AlNd, Mo/Al/Mo, Mo/AlNd/Mo, Ti/Al, Ti/AlNd, Ti/Al/Ti, and Ti/AlNd/Ti.

8. The method of claim 5, wherein the conductive material layer includes at least one multi-layer structure including at least one selected from the group consisting of Mo, Ti, Pt, Cu, Al, W, MoW, AlNd, Ni, Ag, Au, IZO, and ITO, or a silicide thereof.

9. The method of claim 6, wherein the conductive material layer includes at least one multi-layer structure including at least one selected from the group consisting of Mo, Ti, Pt, Cu, Al, W, MoW, AlNd, Ni, Ag, Au, IZO, and ITO, or a silicide thereof.

10. The method of claim 7, wherein the conductive material layer includes at least one multi-layer structure including at least one selected from the group consisting of Mo, Ti, Pt, Cu, Al, W, MoW, AlNd, Ni, Ag, Au, IZO, and ITO, or a silicide thereof.

11. The method of claim 1, wherein the fluoride includes at least one selected from the group consisting of GaF₃, InF₃, and ZnF₂.

12. The method of claim 1, wherein the chloride includes at least one selected from the group consisting of GaCl₃, InCl₃, and ZnCl₂.

13. The method of claim 1, further comprising injecting active oxygen into a surface of the channel layer, before forming the passivation layer.

14. The method of claim 5, further comprising injecting active oxygen into a surface of the channel layer, before forming the passivation layer.

15. The method of claim 6, further comprising injecting active oxygen into a surface of the channel layer, before forming the passivation layer.

16. The method of claim 7, further comprising injecting active oxygen into a surface of the channel layer, before forming the passivation layer.

17. The method of claim 1, before forming the ZnO-based channel layer on the gate insulating layer, further comprising:

forming a gate on a substrate; and

forming a gate insulating layer on the gate.

18. The method of claim 5, before forming the ZnO-based channel layer on the gate insulating layer, further comprising:

forming a gate on a substrate; and

forming a gate insulating layer on the gate.