Thin-film device and method of fabricating the same

• US 7,884,360 B2
• Filed: 08/06/2007
• Issued: 02/08/2011
• Est. Priority Date: 08/09/2006
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd. (Tianma Microelectronics Company Limited)
• Original Assignee: NEC LCD Technologies Limited (Tianma Microelectronics Company Limited)
• Inventors: Takechi, Kazushige, Nakata, Mitsuru
• Primary Examiner(s): MENZ, LAURA MARY
• Application Number:
  US11/890,426
• Publication Number:
  US 20080038882A1
• Time in Patent Office: 1,282 Days
• Field of Search: 257/57, 257/52, 257/66
• US Class Current: 257/57
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02587 Structure
• CPC Class Codes: H01L 21/02694 Controlling the interface between substrate and epitaxial layer, e.g. by ion implantation followed by annealing
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A thin-film device includes a first electrical insulator, an oxide-semiconductor film formed on the first electrical insulator, and a second electrical insulator formed on the oxide-semiconductor film, the oxide-semiconductor film defining an active layer. The oxide-semiconductor film is comprised of a first interface layer located at an interface with the first electrical insulating insulator, a second interface layer located at an interface with the second electrical insulator, and a bulk layer other than the first and second interface layers. A density of oxygen holes in at least one of the first and second interlayer layers is smaller than a density of oxygen holes in the bulk layer.

Claims

1. A thin-film device including a first electrical insulator, an oxide-semiconductor film formed on said first electrical insulator, and a second electrical insulator formed on said oxide-semiconductor film,

said oxide-semiconductor film defining an active layer,

said oxide-semiconductor film being comprised of a first interface layer located at an interface with said first electrical insulator, a second interface layer located at an interface with said second electrical insulator, and a bulk layer other than said first and second interface layers,

wherein oxygen hole densities in both of said first and second interface layers are smaller than a density of oxygen holes in said bulk layer.

2. The thin-film device as set forth in claim 1, wherein said oxide-semiconductor film is composed of amorphous oxide containing at least one of Zn, Ga and In.

3. The thin-film device as set forth in claim 1, wherein said oxide-semiconductor film is composed of crystalline oxide containing at least one of Zn, Ga and In.

4. The thin-film device as set forth in claim 3, wherein said oxide-semiconductor film is formed by crystallizing amorphous oxide with laser irradiation thereto.

5. The thin-film device as set forth in claim 1, wherein said oxide-semiconductor film is formed by dissolving powdered oxide semiconductor into solvent, coating or printing said solvent onto said first electrical insulator, and heating said solvent to vaporize said solvent.

6. The thin-film device as set forth in claim 1, wherein said first electrical insulator, said oxide-semiconductor film, and said second electrical insulator are formed on an electrically insulating substrate.

7. The thin-film device as set forth in claim 6, wherein said electrically insulating substrate is comprised of one of a glass substrate and a resin substrate.

8. The thin-film device as set forth in claim 1, wherein said thin-film device is comprised of one of a thin-film transistor and a thin-film diode.