Semiconductor device and method for manufacturing the same

A semiconductor device comprising:

• a thin film transistor comprising:
• a gate electrode;
• a gate insulating layer over the gate electrode;
• an oxide semiconductor layer over the gate insulating layer;
• a first metal oxide layer over the oxide semiconductor layer;
• a first conductive layer over the first metal oxide layer;
• a second metal oxide layer over the oxide semiconductor layer;
• and
• a second conductive layer over the second metal oxide layer;
• and
• an insulating layer over the oxide semiconductor layer, the insulating layer being in contact with a top surface of the oxide semiconductor layer,
• wherein a gap between the first metal oxide layer and the second metal oxide layer is smaller than a gap between the first conductive layer and the second conductive layer, and
• wherein a top surface of a first portion of the first metal oxide layer is in contact with the first conductive layer, and a top surface and a side surface of an end portion of the first metal oxide layer is not in contact with the first conductive layer.

A semiconductor device comprising:

• a thin film transistor comprising:
• a gate electrode;
• a gate insulating layer over the gate electrode;
• an oxide semiconductor layer over the gate insulating layer;
• a first metal oxide layer over the oxide semiconductor layer;
• a first conductive layer over the first metal oxide layer;
• a second metal oxide layer over the oxide semiconductor layer;
• and
• a second conductive layer over the second metal oxide layer;
• and
• an insulating layer over the oxide semiconductor layer, the first metal oxide layer, the first conductive layer, the second metal oxide layer and the second conductive layer, the insulating layer being in contact with a top surface of the oxide semiconductor layer,
• wherein a gap between the first metal oxide layer and the second metal oxide layer is smaller than a gap between the first conductive layer and the second conductive layer,
• wherein the gate electrode comprises copper,
• wherein the gate insulating layer comprises a first gate insulating layer and a second gate insulating layer over the first gate insulating layer,
• wherein the first gate insulating layer is a silicon nitride film or a silicon nitride oxide film, and
• wherein a top surface of a first portion of the first metal oxide layer is in contact with the first conductive layer, and a top surface and a side surface of an end portion of the first metal oxide layer is not in contact with the first conductive layer.

A semiconductor device comprising:

• a thin film transistor comprising:
• a gate electrode;
• a gate insulating layer over the gate electrode;
• an oxide semiconductor layer over the gate insulating layer;
• a first conductive layer over the oxide semiconductor layer;
• a second conductive layer over the first conductive layer;
• a third conductive layer over the second conductive layer;
• a fourth conductive layer over the oxide semiconductor layer;
• a fifth conductive layer over the fourth conductive layer;
• and
• a sixth conductive layer over the fifth conductive layer;
• and
• an insulating layer over the oxide semiconductor layer, the insulating layer being in contact with a top surface of the oxide semiconductor layer,
• wherein a gap between the first conductive layer and the fourth conductive layer is smaller than a gap between the second conductive layer and the fifth conductive layer,
• wherein the gap between the first conductive layer and the fourth conductive layer is smaller than a gap between the third conductive layer and the sixth conductive layer, and
• wherein a top surface of a first portion of the first conductive layer is in contact with the second conductive layer, and a top surface and a side surface of an end portion of the first conductive layer is not in contact with the second conductive layer.

A semiconductor device comprising:

• a thin film transistor comprising:
• a gate electrode;
• a gate insulating layer over the gate electrode;
• an oxide semiconductor layer over the gate insulating layer;
• a first layered structure electrically connected to the oxide semiconductor layer;
• and
• a second layered structure electrically connected to the oxide semiconductor layer;
• and
• an insulating layer over the oxide semiconductor layer, the first layered structure and the second layered structure, the insulating layer being in contact with a top surface of the oxide semiconductor layer,
• wherein the first layered structure comprises:
• a first conductive layer over the oxide semiconductor layer;
• a second conductive layer over the first conductive layer;
• and
• a third conductive layer over the second conductive layer,
• wherein the second layered structure comprises:
• a fourth conductive layer over the oxide semiconductor layer;
• a fifth conductive layer over the fourth conductive layer;
• and
• a sixth conductive layer over the fifth conductive layer,
• wherein a gap between the first conductive layer and the fourth conductive layer is smaller than a gap between the second conductive layer and the fifth conductive layer,
• wherein the gap between the first conductive layer and the fourth conductive layer is smaller than a gap between the third conductive layer and the sixth conductive layer,
• wherein the first layered structure comprises copper,
• wherein the second layered structure comprises copper,
• wherein the gate insulating layer comprises a first gate insulating layer and a second gate insulating layer over the first gate insulating layer,
• wherein the first gate insulating layer is a silicon nitride film or a silicon nitride oxide film, and
• wherein a top surface of a first portion of the first conductive layer is in contact with the second conductive layer, and a top surface and a side surface of an end portion of the first conductive layer is not in contact with the second conductive layer.