THIN FILM TRANSISTOR HAVING CRYSTALLINE INDIUM OXIDE SEMICONDUCTOR FILM

• US 20100065835A1
• Filed: 09/18/2008
• Published: 03/18/2010
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Utsuno, Futoshi, Kawashima, Hirokazu, Goto, Kenji, Kasami, Masashi, Inoue, Kazuyoshi, Yano, Koki, Tomai, Shigekazu
• Granted Patent: US 9,269,573 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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

To provide a thin film transistor having an indium oxide-based semiconductor film which allows only a thin metal film on the semiconductor film to be selectively etched. A thin film transistor having a crystalline indium oxide semiconductor film which is composed mainly of indium oxide and contains a positive trivalent metal oxide.

Claims

1. A thin film transistor having a crystalline indium oxide semiconductor film which is composed mainly of indium oxide and contains a positive trivalent metal oxide, having an atomic ratio of metal element M in the positive trivalent metal oxide to the total amount of indium In in the indium oxide plus the metal element M in the positive trivalent metal oxide M/(M+In) of 0.0001 to 0.1.

2. The thin film transistor according to 1, wherein the positive trivalent metal oxide is one or two or more of boron oxide, aluminum oxide, gallium oxide, scandium oxide, yttrium oxide, lanthanum oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide or lutetium oxide.

8. The thin film transistor according to claim 1, wherein the semiconductor film is an epitaxial or polycrystalline film.

9. The thin film transistor according to claim 1, wherein the semiconductor film is a polycrystalline film.

10. The thin film transistor according to claim 9, wherein the film is formed of nanocrystals.

11. The thin film transistor according to 1, wherein the positive trivalent metal oxide is one or two or more of aluminum oxide, gallium oxide, yttrium oxide, samarium oxide, dysprosium oxide, holmium oxide, erbium oxide, or ytterbium oxide.

12. The thin film transistor according to 1, wherein the positive trivalent metal oxide is one or two or more of gallium oxide, yttrium oxide, or ytterbium oxide.

3. (canceled)

4. A method for producing the thin film transistor according to any one of 1 to 3 comprising:

forming a semiconductor film containing indium oxide and a positive trivalent metal oxide; and

oxidizing the semiconductor film and/or crystallizing the semiconductor film.

5. The method for producing the thin film transistor according to 4, wherein the semiconductor film is subjected to a heat treatment at 150°

C. to 450°

C. for 0.5 to 1200 minutes in the presence of oxygen.

6. The method for producing the thin film transistor according to 4 or 5 which produces a channel-etch type thin film transistor.

7. The method for producing the thin film transistor according to 4 or 5 which produces an etch stopper-type thin film transistor.