METHOD OF FABRICATING ZnO FILM AND THIN FILM TRANSISTOR ADOPTING THE ZnO FILM

• US 20070172591A1
• Filed: 01/19/2007
• Published: 07/26/2007
• Est. Priority Date: 01/21/2006
• Status: Abandoned Application

• Current Assignee: Ajou University Industry Cooperation Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Ajou University Industry Cooperation Foundation, Samsung Electronics Co. Ltd.
• Inventors: JO, Jungyol, SEO, O-gweon
• Application Number:
  US11/625,016
• Publication Number:
  US 20070172591A1
• Time in Patent Office: Days
• US Class Current: 427/248.100
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/407 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• 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 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• 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 fabricating a low temperature ZnO polycrystalline film and a thin film transistor (TFT) adopting the low temperature ZnO polycrystalline film. The method includes growing ZnO on a substrate at a first temperature for a first time using Metal Organic Chemical Vapor Deposition (MOCVD) to form a ZnO buffer layer, and heating the substrate at a temperature lower than the first temperature to grow ZnO on the ZnO buffer layer for a second time longer than the first time so as to form a ZnO film.

Claims

1. A method of fabricating a ZnO film, comprising:

growing ZnO on a substrate at a first temperature for a first time using MOCVD (Metal Organic Chemical Vapor Deposition) to form a ZnO buffer layer; and

heating the substrate at a temperature lower than the first temperature to grow ZnO on the ZnO buffer layer for a second time longer than the first time so as to form a ZnO film.

2. The method of claim 1, wherein the first temperature is greater than or equal to 300°

C., and the second temperature is less than or equal to 300°

C.

3. The method of claim 1, wherein the substrate is plastic or silicon.

4. The method of claim 1, wherein the second temperature is about 250°

C.

5. The method of claim 1, wherein a thickness of the ZnO buffer layer is within a range between 1 nm and 1,000 nm.

6. The method of claim 1, wherein DEZ (diethylzinc) is used as a precursor for growing the ZnO.

7. The method of claim 6, wherein when the ZnO buffer layer is grown, O₂:

DEZ are supplied in a flow ratio of greater than or equal to about 1,000;

1.

8. The method of claim 7, wherein when the ZnO film is grown, O₂:

DEZ are supplied in a flow ratio of greater than or equal to about 1800;

1.

9. The method of claim 4, wherein when the ZnO film is grown, O₂:

DEZ are supplied in a flow ratio of greater than or equal to 1,000;

1.

10. The method of claim 9, wherein when the ZnO film is grown, O₂:

DEZ are supplied in a flow ratio of greater than or equal to about 1,800;

1.

11. A method of fabricating a ZnO TFT (thin film transistor) comprising a substrate, a ZnO semiconductor layer formed on a surface of the substrate, a source and a drain disposed on and contacting a surface of the ZnO semiconductor layer opposite the substrate, and a gate forming an electric field around the ZnO semiconductor layer, comprising:

forming the ZnO semiconductor layer by;

growing ZnO on the substrate at a first temperature for a first time using MOCVD to form a ZnO buffer layer; and

heating the substrate at a temperature lower than the first temperature to grow ZnO on the ZnO buffer layer for a second time longer than the first time so as to form a ZnO film.

12. The method of claim 11, wherein the first temperature is greater than or equal to 300°

C., and the second temperature is greater than or equal to 300°

C.

13. The method of claim 11, wherein the substrate is silicon or plastic.

14. The method of claim 11, wherein the second temperature is about 250°

C.

15. The method of claim 11, wherein DEZ is used as a precursor for growing the ZnO.

16. The method of claim 15, wherein when the ZnO film is grown, O₂:

DEZ are supplied in a flow ratio of greater than or equal to about 1,000;

1.

17. The method of claim 16, wherein O₂:

DEZ is supplied in a flow ratio of about 1,800;

1.