Patent ID: 11869981
Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A semiconductor device comprising:
a substrate;
a first conductive layer over the substrate;
a first insulating layer over the first conductive layer;
an oxide semiconductor layer over the first insulating layer;
a second conductive layer over the oxide semiconductor layer;
a third conductive layer over the oxide semiconductor layer; and
a second insulating layer over the second conductive layer and the third conductive layer,
wherein the oxide semiconductor layer comprises a first oxide semiconductor film and a second oxide semiconductor film,
wherein the second oxide semiconductor film comprises a region having lower crystallinity than the first oxide semiconductor film,
wherein the second oxide semiconductor film is a composite oxide semiconductor,
wherein the composite oxide semiconductor comprises:
a first region comprising InaMbZncOd; and
a second region comprising InxZnyOz,

wherein the a, b, c, d, x, y, and z each represent a given number,
wherein the M represents Al, Ga, Y, or Sn, and
wherein a concentration of indium in the second region is higher than a concentration of indium in the first region.