Transparent oxide semiconductor thin film transistor

• US 7,470,607 B2
• Filed: 10/10/2003
• Issued: 12/30/2008
• 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: Carcia, Peter Francis, McLean, Robert S.
• Primary Examiner(s): Estrada; Michelle
• Application Number:
  US10/527,173
• Publication Number:
  US 20060035452A1
• Time in Patent Office: 1,908 Days
• Field of Search: 438/608, 438/609, 257/E33.064, 257/E31.126
• US Class Current: 438/609
• 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 comprising:

depositing an undoped transparent oxide semiconductor,

comprising at least one oxide selected from the group consisting of zinc oxide,

indium oxide, tin oxide, and cadmium oxide, in a field effect transistor, by a method selected from the group consisting of;

a) physical vapor deposition of an undoped transparent oxide semiconductor in a controlled partial pressure of oxygen of 0.1 P_c to 10 P_c, in an inert gas;

b) resistive evaporation of an undoped transparent oxide semiconductor in a controlled partial pressure of oxygen of 0.1P_c to 10P_c;

c) laser evaporation of an undoped transparent oxide semiconductor in a controlled partial pressure of oxygen of 0.1 P_c to 10 P_c, in an inert gas;

d) electron beam evaporation of an undoped transparent oxide semiconductor in a controlled partial pressure of oxygen of 0.1 P_c to 10 P_c, in an inert gas; and

e) chemical vapor deposition of an undoped transparent oxide semiconductor in a controlled partial pressure of oxygen of 0.1 P_c to 10 P_c, in an inert gas, wherein P_c is oxygen critical pressure.

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

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

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

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

6. The process of claim 1 wherein 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) wherein the chemical vapor deposition is atomic layer chemical vapor deposition.

12. The process of claim 1 wherein the effective partial pressure of oxygen is between 0.5 and 2 times the critical pressure.