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

Claim 1:
2. A semiconductor device comprising:
a substrate;
an oxide semiconductor layer over the substrate;
a first conductive layer electrically connected to the oxide semiconductor layer;
a second conductive layer electrically connected to the oxide semiconductor layer;
a first insulating layer over the oxide semiconductor layer;
a third conductive layer over the first insulating layer; and
a second insulating layer over 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,
wherein the first region and the second region have different compositions,
wherein the second region has an island-like shape, and
wherein the second region is surrounded by the first region.