Field-effect transistor

• US 7,851,792 B2
• Filed: 11/01/2006
• Issued: 12/14/2010
• Est. Priority Date: 11/08/2005
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sano, Masafumi, Kaji, Nobuyuki, Aiba, Toshiaki
• Primary Examiner(s): Ngo; Ngan
• Assistant Examiner(s): LIU, BENJAMIN T
• Application Number:
  US12/089,907
• Publication Number:
  US 20090272970A1
• Time in Patent Office: 1,504 Days
• Field of Search: 257/43, 257/E29.296, 257/52, 257/57, 257/213, 257/E29.08
• US Class Current: 257/43
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• 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

Provided is a field-effect transistor including an active layer and a gate insulating film, wherein the active layer includes an amorphous oxide layer containing an amorphous region and a crystalline region, and the crystalline region is in the vicinity of or in contact with an interface between the amorphous oxide layer and the gate insulating film.

Claims

1. A field-effect transistor comprising:

an active layer, and

a gate insulating film,

wherein the active layer comprises an amorphous oxide layer containing In, Zn an Ga and includes an amorphous region and a crystalline region,

wherein the crystalline region exists in a dotted state within a distance of ½

or less of a thickness of the active layer from a first interface which is an interface between the amorphous oxide layer and the gate insulating film and within 300 nm from an interface between the active layer and the gate insulating film, or exists in a dotted state in contact with the first interface, and

wherein the crystalline region is absent in a vicinity of a second interface opposed to the first interface.

2. A field-effect transistor according to claim 1, wherein the amorphous oxide layer has a thickness of 0.05 μ

m or more and 1 μ

m or less.