US Patent No. 9,130,049

AMORPHOUS OXIDE AND FIELD EFFECT TRANSISTOR


Patent No. 9,130,049
Issue Date September 08, 2015
Title Amorphous Oxide And Field Effect Transistor
Inventorship Masafumi Sano, Kanagawa-Ken (JP)
Katsumi Nakagawa, Kanagawa-Ken (JP)
Hideo Hosono, Kanagawa-Ken (JP)
Toshio Kamiya, Kanagawa-Ken (JP)
Kenji Nomura, Kanagawa-Ken (JP)
Assignee Canon Kabushiki Kaisha, Tokyo (JP) Tokyo Institute of Technology, Tokyo (...

Claim of US Patent No. 9,130,049

1. A field effect transistor comprising:
a gate electrode,
a gate insulator, and
an active layer of an amorphous oxide selected from the group consisting of an amorphous oxide containing In, Zn and Sn; an
amorphous oxide containing In and Zn; an amorphous oxide containing In and Sn; an amorphous oxide containing In; and an amorphous
oxide containing In, Ga and Zn,

wherein the active layer has a composition varying in a layer thickness direction such that the concentration of at least
one of In, Zn and oxygen is higher in the region close to the gate insulator than in the region away from the gate insulator,
and

wherein the active layer has an electron carrier concentration of 1012/cm3 or more and less than 1018/cm3.