Transparent oxide semiconductor thin film transistors

• US 20040127038A1
• Filed: 09/24/2003
• Published: 07/01/2004
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: McLean, Robert Scott, Carcia, Peter Francis
• Granted Patent: US 7,067,843 B2
• Time in Patent Office: Days
• US Class Current: 438/689
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• 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 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

This invention relates to novel, transparent oxide semiconductor thin film transistors (TFT'"'"'s) and a process for making them.

Claims

1. A process for depositing undoped transparent oxide semiconductors, selected from the group consisting of zinc oxide, indium oxide, tin oxide, and cadmium oxide, in a field effect transistor, comprising a method selected from the group consisting of:

a) physical vapor deposition of undoped TOS in an effective partial pressure of oxygen mixed with an inert gas;

b) resistive evaporation of undoped TOS in an effective partial pressure of oxygen;

c) laser evaporation of undoped TOS in an effective partial pressure of oxygen;

d) electron beam evaporation of undoped T-OS in an effective partial pressure of oxygen; and

e) chemical vapor deposition of undoped T-OS in an effective partial pressure of oxygen.

2. The process of claim 1 where the physical vapor deposition is rf magnetron sputtering.

3. The process of claim 1 where the physical vapor deposition is dc magnetron sputtering.

4. The process of claim 1 where the physical vapor deposition is diode sputtering.

5. The process of claim 1 where the physical vapor deposition is triode sputtering.

6. The process of claim 1 where the physical vapor deposition is ion beam sputtering.

7. The process of any of claims 1(a), 2, 3, 4, 5 or 6 wherein deposition is by physical vapor deposition and wherein the inert gas is selected from the group consisting of helium, neon, argon, krypton, and xenon.

8. The process of claim 1(e) wherein the chemical vapor deposition is low pressure chemical vapor deposition.

9. The process of claim 1(e) wherein the chemical vapor deposition is plasma-enhanced chemical vapor deposition.

10. The process of claim 1(e) wherein the chemical vapor deposition is laser-enhanced chemical vapor deposition.

11. The process of claim 1(e) where the chemical vapor deposition is atomic layer chemical vapor deposition.

12. The process of any one of claims 1 to 11 wherein the effective partial pressure of oxygen is between 0.1 and 10 times the critical pressure.

13. The process of any one of claims 1 to 11 wherein the effective partial pressure of oxygen is between 0.5 and 2 times the critical pressure.

15. A transistor comprising a transparent oxide semiconductor made by a process selected from the group of process consisting of the process as of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13.

14. A transistor comprising an undoped transparent oxide semiconductor.

16. A flat panel display comprising one or an array of transparent oxide semiconductor transistors as described by claim 14.

17. An active matrix imager comprising an array of transparent oxide semiconductor transistors as described by claim 14.

18. A sensor comprising an array of transparent oxide semiconductor transistors as described by claim 14.

19. A rf price label comprising an array of transparent oxide semiconductor transistors as described by claim 14.

20. A rf identification tag comprising an array of transparent oxide semiconductor transistors as described by claim 14.

21. A rf inventory tag comprising an array of transparent oxide semiconductor transistors as described by claim 14.

22. The transistor of claim 14 deposited on a flexible substrate.

23. The transistor of claim 14 or claim 15 further comprising source, drain and gate electrodes fabricated from a material selected from the group consisting of zinc oxide, indium oxide, tin oxide, and cadmium oxide.

24. The transistor of claim 22 further comprising a gate dielectric fabricated from a material selected from the group consisting of zinc oxide, indium oxide, tin oxide, and cadmium oxide.