Oxide-based thin film transistor, method of fabricating the same, zinc oxide etchant, and a method of forming the same

• US 20080315193A1
• Filed: 05/01/2008
• Published: 12/25/2008
• Est. Priority Date: 06/22/2007
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Eun-ha, Park, Young-soo, Park, Jae-chul, Kim, Chang-jung
• Application Number:
  US12/149,409
• Publication Number:
  US 20080315193A1
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: C09K 13/06 with organic material
• CPC Class Codes: H01L 21/467 using masks
• 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 zinc (Zn) oxide-based thin film transistor that may include a gate, a gate insulating layer on the gate, a channel including zinc oxide and may be on a portion of the gate insulating layer, and a source and drain contacting respective sides of the channel. The zinc (Zn) oxide-based thin film transistor may further include a recession in the channel between the source and the drain, and a zinc oxide-based etchant may be used to form the recession.

Claims

1. A zinc oxide-based etchant comprising an aqueous mixture solution of CH₃COOH and at least one of HCl, HF, and P₂O₅.

2. The zinc oxide-based etchant of claim 1, wherein the amount of the at least one of HCl, HF, and P₂O₅ is in the range from about 0.1 to about 1 vol %.

3. The zinc oxide-based etchant of claim 1, wherein the amount of CH₃COOH is in the range from about 5 to about 50 vol %.

4. A zinc (Zn) oxide-based thin film transistor comprising:

a gate;

a gate insulating layer on the gate;

a channel including zinc oxide on a portion of the gate insulating layer; and

a source and drain contacting sides of the channel;

the channel further including a recession between the source and drain.

5. The zinc oxide-based thin film transistor of claim 4, wherein the recession has a step with respect to portions of the channel contacting the source and the drain.

6. The zinc oxide-based thin film transistor of claim 4, wherein the recession is formed by a wet etching process using a zinc oxide-base etchant including an aqueous mixture solution of CH₃COOH and at least one of HCl, HF, and P₂O₅.

7. The zinc oxide-based thin film transistor of claim 6, wherein the amount of the at least one of HCl, HF, and P₂O₅ is in the range from about 0.1 to about 1 vol %.

8. The zinc oxide-based thin film transistor of claim 6, wherein the amount of CH₃COOH is in the range of about 5 to about 50 vol %.

9. The zinc oxide-based thin film transistor of claim 4, wherein the zinc oxide is ZnO, InZnO, or GaInZnO.

10. A method of fabricating a thin film transistor, the method comprising:

forming a gate;

forming a gate insulating layer on the gate;

forming a channel including zinc oxide on a portion of the gate insulating layer;

forming a source and drain by coating a conductive material on the gate insulating layer and the channel and etching the conductive material on the channel; and

forming a recession by etching a surface of the channel exposed between the source and the drain.

11. The method of claim 10, wherein forming the recession includes providing a step with respect to portions of the channel contacting the source and drain.

12. The method of claim 10, wherein the zinc oxide is ZnO, InZnO, or GaInZnO.

13. The method of claim 12, wherein forming the recession by etching includes a wet etching process using a zinc oxide-based etchant including an aqueous mixture solution of CH₃COOH and at least one of HCl, HF, and P₂O₅.

14. The method of claim 13, wherein the amount of the at least one of HCl, HF, and P₂O₅ is in the range from about 0.1 to about 1 vol %.

15. The method of claim 13, wherein the amount of CH₃COOH is in the range from about 5 to about 50 vol %.

16. A method of forming a zinc oxide-based etchant comprising:

mixing at least one of HCl, HF, and P₂O₅ with deionized water; and

mixing CH₃COOH with the mixture of at least one of HCl, HF, and P₂O₅ and deionized water.

17. The method of claim 16, wherein the amount of the at least one of HCl, HF, and P₂O₅ is at least 1 ml and the deionized water is at least 99 ml in the zinc oxide-based etchant.

18. The method of claim 16, wherein at least 10 ml of the CH₃COOH is mixed with the mixture of at least one of HCl, HF, and P₂O₅ and deionized water.

19. The method of claim 16, wherein the amount of the at least one of HCl, HF, and P₂O₅ is in the range from about 0.1 to about 1 vol %.

20. The method of claim 16, wherein the amount of the CH₃COOH is in the range from about 5 to about 50 vol %.