THIN-FILM TRANSISTOR FABRICATION PROCESS AND DISPLAY DEVICE

• US 20100044701A1
• Filed: 02/18/2008
• Published: 02/25/2010
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sano, Masafumi, Hayashi, Ryo
• Granted Patent: US 8,436,349 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• 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

In a process for fabricating a thin-film transistor in which a gate electrode 4 is to be formed on a substrate 1, the process has the steps of forming the gate electrode 4 on the substrate 1, forming a metal oxide layer 7 in such a way as to cover the gate electrode 4, forming a source electrode 6 and a drain electrode 5, and carrying out annealing in an inert gas to change part of the metal oxide layer 7 into a channel region.

Claims

1. A process for fabricating a thin-film transistor in which a gate electrode is to be formed on a substrate, the process comprising the steps of:

forming the gate electrode on the substrate;

forming a metal oxide layer in such a way as to cover the gate electrode;

forming a source electrode and a drain electrode; and

carrying out heat treatment in an inert gas to change part of the metal oxide layer into a channel region.

3. The process for fabricating a thin-film transistor according to claim 1, wherein the metal oxide layer comprises Zn as a material.

4. The process for fabricating a thin-film transistor according to claim 3, wherein the metal oxide layer further comprises at least one of In, Ga, Al, Fe, Sn, Mg, Ca, Si and Ge, has a resistivity of 10⁸ Ω

·

cm or more, and is amorphous.

5. The process for fabricating a thin-film transistor according to claim 4, wherein the inert gas is Ar gas.

6. A display device comprising:

a display element; and

a thin-film transistor fabricated by a process according to claim 1,

wherein the source electrode or the drain electrode of the thin-film transistor is connected to an electrode of the display element.

7. The display device according to claim 6, wherein the display element is an electroluminescent element.

8. The display device according to claim 6, wherein the display element is a liquid-crystal cell.

2. A process for fabricating a thin-film transistor in which a gate electrode is to be formed on a substrate, the process comprising the steps of:

forming the gate electrode on the substrate;

forming a gate insulating film in such a way as to cover the gate electrode;

forming a metal oxide layer on the gate insulating film;

forming a source electrode and a drain electrode; and

carrying out heat treatment in an inert gas to change part of the metal oxide layer into a channel region.

9. The process for fabricating a thin-film transistor according to claim 2, wherein the metal oxide layer comprises Zn as a material.

10. The process for fabricating a thin-film transistor according to claim 9, wherein the metal oxide layer further comprises at least one of In, Ga, Al, Fe, Sn, Mg, Ca, Si and Ge, has a resistivity of 10⁸ Ω

·

cm or more, and is amorphous.

11. The process for fabricating a thin-film transistor according to claim 10, wherein the inert gas is Ar gas.

12. A display device comprising:

a display element; and

a thin-film transistor fabricated by a process according to claim 2,

wherein the source electrode or the drain electrode of the thin-film transistor is connected to an electrode of the display element.

13. The display device according to claim 12, wherein the display element is an electroluminescent element.

14. The display device according to claim 12, wherein the display element is a liquid-crystal cell.