Semiconductor device comprising transitor, capacitor and plug

Abstract

A semiconductor device with little characteristic variation is provided. A transistor includes an oxide semiconductor; a first conductor and a second conductor over the oxide semiconductor; a first insulator over the first conductor; a second insulator over the second conductor; a third insulator that is positioned over the first insulator and the second insulator and provided with a first opening overlapping with a region between the first conductor and the second conductor; a fourth insulator positioned over the oxide semiconductor and between the first conductor and the second conductor; and a third conductor over the fourth insulator. A capacitor includes the second conductor; the third insulator provided with a second opening reaching the second conductor; a fifth insulator positioned inside the second opening; and a fourth conductor over the fifth insulator. A plug is positioned to penetrate the first insulator, the third insulator, the first conductor, and the oxide semiconductor. The plug is electrically connected to the first conductor. The first insulator and the second insulator are each formed using a metal oxide including an amorphous structure.