Semiconductor device

A semiconductor device comprising:

• a transistor;
• a capacitor;
• and
• a plug,
• wherein the transistor comprises:
• an oxide semiconductor;
• a first conductor and a second conductor over the oxide semiconductor;
• a first insulator provided with a first opening overlapping with a region between the first conductor and the second conductor;
• a second insulator over the oxide semiconductor and inside the first opening;
• and
• a third conductor over the second insulator,
• wherein the capacitor comprises:
• the second conductor;
• the first insulator provided with a second opening reaching the second conductor;
• a third insulator inside the second opening;
• and
• a fourth conductor over the third insulator,
• wherein the third insulator is in contact with a top surface of the second conductor,
• wherein the plug is positioned to penetrate the first insulator, the first conductor, and the oxide semiconductor, and
• wherein the plug is electrically connected to the first conductor.

A semiconductor device comprising:

• a transistor;
• and
• a capacitor,
• wherein the transistor comprises:
• an oxide semiconductor;
• a first conductor and a second conductor over the oxide semiconductor;
• a first insulator provided with a first opening overlapping with a region between the first conductor and the second conductor;
• a second insulator over the oxide semiconductor and inside the first opening;
• and
• a third conductor over the second insulator,
• wherein the capacitor comprises:
• the second conductor;
• the first insulator provided with a second opening reaching the second conductor;
• a third insulator inside the second opening;
• and
• a fourth conductor over the third insulator,
• wherein the third insulator is in contact with a top surface and a side surface of the second conductor and a side surface of the oxide semiconductor.