US 12,170,288 B2
Semiconductor device
Yohei Yamaguchi, Tokyo (JP)
Assigned to Japan Display Inc., Tokyo (JP)
Filed by Japan Display Inc., Tokyo (JP)
Filed on Oct. 3, 2022, as Appl. No. 17/958,515.
Application 17/958,515 is a continuation of application No. 16/733,435, filed on Jan. 3, 2020, granted, now 11,488,984.
Claims priority of application No. 2019-002537 (JP), filed on Jan. 10, 2019.
Prior Publication US 2023/0027596 A1, Jan. 26, 2023
Int. Cl. H01L 27/12 (2006.01); G02F 1/1333 (2006.01); G02F 1/1362 (2006.01); H01L 21/02 (2006.01); H01L 21/311 (2006.01); H01L 21/822 (2006.01)
CPC H01L 27/124 (2013.01) [G02F 1/133345 (2013.01); G02F 1/136227 (2013.01); G02F 1/136286 (2013.01); H01L 21/02554 (2013.01); H01L 21/02565 (2013.01); H01L 21/31116 (2013.01); H01L 21/822 (2013.01); H01L 27/1225 (2013.01); G02F 1/136295 (2021.01); G02F 2201/123 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A semiconductor device comprising:
a base layer;
an oxide semiconductor layer above the base layer, the oxide semiconductor layer having an edge;
a first conductive layer above the oxide semiconductor layer;
a first insulating layer above the first conductive layer; and
a second conductive layer above the first insulating layer,
wherein the oxide semiconductor layer forms a part of a thin film transistor,
the first conductive layer overlaps the edge of the oxide semiconductor layer in a plan view and has a step tracing the edge of the oxide semiconductor layer in a cross sectional view,
the first conductive layer is directly in contact with the edge and an upper surface of the oxide semiconductor layer,
the first insulating layer has a first opening overlapping the edge of the oxide semiconductor layer in the plan view,
the first opening exposes the first conductive layer,
the second conductive layer overlaps the first opening and the edge of the oxide semiconductor layer in the plan view and is directly in contact with the first conductive layer at the first opening,
the first insulating layer has an upper surface in contact with the second conductive layer and a bottom surface,
the upper surface of the first insulating layer has a first upper surface overlapping the oxide semiconductor layer and a second upper surface not overlapping the oxide semiconductor layer, and
a first distance between the base layer and the first upper surface is larger than a second distance between the base layer and the second upper surface,
wherein the first conductive layer is a source electrode or a drain electrode of a transistor,
the first conductive layer includes a first film, a second film below the first film and a third film below the second film,
a part of a surface of the first film on the second film side is exposed from the second film, and
the second conductive layer directly contacts the third film at the first opening,
further comprising:
a gate electrode opposing the oxide semiconductor layer;
a gate insulating layer between the oxide semiconductor layer and the gate electrode; and
a third conductive layer connected to the oxide semiconductor layer,
wherein the oxide semiconductor layer is connected to the first conductive layer, and
the oxide semiconductor layer is arranged between the first conductive layer and the third conductive layer.