Method of fabricating oxide semiconductor device

• US 7,468,304 B2
• Filed: 08/24/2006
• Issued: 12/23/2008
• Est. Priority Date: 09/06/2005
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kaji, Nobuyuki, Yabuta, Hisato
• Primary Examiner(s): Le; Thao P.
• Application Number:
  US11/466,950
• Publication Number:
  US 20070054507A1
• Time in Patent Office: 852 Days
• Field of Search: 438/308, 438/149, 257/E29.151
• US Class Current: 438/308
• 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 21/02675 using laser beams
• CPC Class Codes: H01L 21/02689 using particle beams
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/3115 Doping the insulating layers
• CPC Class Codes: H01L 21/428 using electromagnetic radiation, e.g. laser radiation
• 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 method for fabricating a device using an oxide semiconductor, including a process of forming the oxide semiconductor on a substrate and a process of changing the conductivity of the oxide semiconductor by irradiating a predetermined region thereof with an energy ray.

Claims

1. A method for fabricating a device using an oxide semiconductor, the method comprising the steps of:

forming the oxide semiconductor on a substrate; and

changing the conductivity of the oxide semiconductor by irradiating a predetermined region of the oxide semiconductor with an energy ray;

wherein the process of changing the conductivity of the oxide semiconductor comprises the steps of;

bringing a photocatalyst into contact with the predetermined region of the oxide semiconductor; and

decreasing the conductivity of the oxide semiconductor by irradiating the photocatalyst with light having an energy equal to or greater than the optical band-gap of the photocatalyst.

2. The method according to claim 1, wherein the device is an oxide-semiconductor channel field-effect transistor;

and the region for decreasing the conductivity of the oxide semiconductor is a channel placed between a source and a drain of the field-effect transistor.

3. The method according to claim 1, wherein the irradiated light used for decreasing the conductivity of the oxide semiconductor is ultraviolet light.

4. The method according to claim 1, wherein the photocatalyst is a material containing titanium oxide.

5. The method according to claim 1, wherein the photocatalyst is a photocatalyst mask processed into a predetermined shape and disposed on the substrate.

6. The method according to claim 1, wherein the oxide semiconductor contains at least one element selected from zinc, indium, and gallium as a constituent element.