PRODUCTION METHOD OF THIN FILM TRANSISTOR USING AMORPHOUS OXIDE SEMICONDUCTOR FILM

• US 20090325341A1
• Filed: 07/26/2007
• Published: 12/31/2009
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sano, Masafumi, Kaji, Nobuyuki, Hayashi, Ryo, Den, Toru, Itagaki, Naho
• Granted Patent: US 8,415,198 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• 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

A production method of a thin film transistor including an active layer including an amorphous oxide semiconductor film, wherein a step of forming the active layer includes a first step of forming the oxide film in an atmosphere having an introduced oxygen partial pressure of 1×10⁻³ Pa or less, and a second step of annealing the oxide film in an oxidative atmosphere after the first step.

Claims

1. A production method of a thin film transistor comprising an active layer comprising an amorphous oxide semiconductor film including at least one element of In and Zn, the production method comprising a step of:

forming the active layer comprising;

a first step of forming the oxide film in an atmosphere having an introduced oxygen partial pressure of 1×

10<sup>−

3</sup> Pa or less; and

a second step of annealing the oxide film in an oxidative atmosphere.

7. The production method of a thin film transistor according to claim 1, wherein the second step makes a treatment in an atmosphere comprising a gas comprising oxygen as a constituent element thereof in a temperature range of 250°

C. or higher and 450°

C. or lower.

8. The production method of a thin film transistor according to claim 1, wherein the second step comprises a step in which the amorphous oxide semiconductor film is irradiated with oxygen radical or ozone and also annealed in a temperature range of 150°

C. or higher and 450°

C. or lower.

9. The production method of a thin film transistor according to claim 1, wherein the second step comprises a step in which in an atmosphere comprising ozone the amorphous oxide semiconductor film is irradiated with ultraviolet light and also annealed in a temperature range of 150°

C. or higher and 450°

C. or lower.

10. The production method of a thin film transistor according to claim 1, wherein the amorphous oxide semiconductor film comprises at least one of Ga and Sn.

11. The production method of a thin film transistor according to claim 1, wherein the amorphous oxide semiconductor film has an atomic composition ratio In/(In+Zn) of 30 atom % or more and 45 atom % or less.

13. The production method of a thin film transistor according to claim 1, wherein the temperature of the first step at which temperature the active layer is formed is equal to or lower than the annealing temperature of the second step.

2. A production method of a thin film transistor comprising an active layer comprising an amorphous oxide semiconductor film including at least one element of In and Zn, the production method comprising:

a first step of forming the oxide film having a first resistivity; and

a second step of converting the resistivity of the oxide film to a second resistivity by annealing in an oxidative atmosphere;

wherein the second resistivity is higher than the first resistivity.

4. The production method of a thin film transistor according to claim 2, wherein the introduced oxygen partial pressure in the atmosphere of the first step is 1×

10<sup>−

3</sup> Pa or less.

5. The production method of a thin film transistor according to claim 2, wherein the first resistivity is 1×

10<sup>−

4</sup> Ω

cm or more and 1 Ω

cm or less, and the second resistivity is 1 Ω

cm or more and 1×

10⁴ Ω

cm or less.

3. A production method of a thin film transistor comprising an active layer comprising an amorphous oxide semiconductor film including at least one element of In and Zn, the production method comprising:

a first step of forming the oxide film having a first activation energy; and

a second step of converting the activation energy of the oxide film to a second activation energy by annealing in an oxidative atmosphere;

wherein the second activation energy is higher than the first activation energy.

6. The production method of a thin film transistor according to claim 3, wherein the first activation energy is 0 meV or more and 50 meV or less at room temperature, and the second activation energy is 50 meV or more and 400 meV or less at room temperature.

12. A production method of a thin film transistor comprising an active layer comprising an amorphous oxide semiconductor film including at least one element of In and Zn, the production method comprising:

a first step of forming the active layer;

a second step of annealing in an oxidative atmosphere; and

a third step of forming an oxide insulating layer on the active layer.

14. The production method of a thin film transistor according to claim 12, wherein the temperature of the third step at which temperature the oxide insulating layer is formed is equal to or lower than the annealing temperature of the second step.