Patent ID: 11888073
Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A semiconductor device comprising:
a first transistor; and
a second transistor over the first transistor, the second transistor electrically connected to the first transistor,
wherein the first transistor comprises silicon in a channel formation region,
wherein the second transistor comprises:
a first insulating layer over the first transistor;
an oxide semiconductor layer over the first insulating layer;
a second insulating layer over the oxide semiconductor layer, the second insulating layer having an opening;
a gate electrode, a first part of the gate electrode provided in the opening; and
a gate insulating layer provided between the oxide semiconductor layer and the gate electrode,

wherein the first insulating layer comprises a first region overlapped with the oxide semiconductor layer and a second region not overlapped with the oxide semiconductor layer,
wherein a thickness of the first region of the first insulating layer is larger than a thickness of the second region of the first insulating layer,
wherein, in a cross section parallel to a channel width direction of the second transistor, a second part of the gate electrode does not overlap with the oxide semiconductor layer, and
wherein, in the cross section parallel to the channel width direction of the second transistor, a bottom surface of the second part of the gate electrode is located below a bottom surface of the oxide semiconductor layer.