Semiconductor device and method for manufacturing the same

A semiconductor device comprising:

• a first metal oxide layer;
• an oxide semiconductor layer over the first metal oxide layer;
• a second metal oxide layer over the oxide semiconductor layer;
• a source electrode and a drain electrode each over the second metal oxide layer;
• a gate electrode;
• an insulating film between the gate electrode and a stack of the first metal oxide layer, the oxide semiconductor layer, and the second metal oxide layer;
• a first low-resistance region between the source electrode and the oxide semiconductor layer;
• and
• a second low-resistance region between the drain electrode and the oxide semiconductor layer,
• wherein the oxide semiconductor layer comprises indium,
• wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor layer,
• wherein the first low-resistance region is in contact with the source electrode,
• wherein the second low-resistance region is in contact with the drain electrode,
• wherein the first low-resistance region has a resistance lower than a region between the first low-resistance region and the second low-resistance region, and
• wherein the second low-resistance region has a resistance lower than the region between the first low-resistance region and the second low-resistance region.

A semiconductor device comprising:

• a first metal oxide layer;
• an oxide semiconductor layer over the first metal oxide layer;
• a source electrode and a drain electrode over the oxide semiconductor layer;
• a second metal oxide layer over the source electrode and the drain electrode;
• a gate electrode;
• an insulating film between the gate electrode and a stack of the first metal oxide layer, the oxide semiconductor layer, and the second metal oxide layer;
• a first low-resistance region between the source electrode and the oxide semiconductor layer;
• and
• a second low-resistance region between the drain electrode and the oxide semiconductor layer,
• wherein the oxide semiconductor layer comprises indium,
• wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor layer,
• wherein the first low-resistance region is in contact with the source electrode,
• wherein the second low-resistance region is in contact with the drain electrode,
• wherein the first low-resistance region has a resistance lower than a region between the first low-resistance region and the second low-resistance region, and
• wherein the second low-resistance region has a resistance lower than the region between the first low-resistance region and the second low-resistance region.