Semiconductor device and manufacturing method thereof
A transistor with stable electrical characteristics. A semiconductor device includes a first insulator over a substrate, a second insulator over the first insulator, an oxide semiconductor in contact with at least part of a top surface of the second insulator, a third insulator in contact with at least part of a top surface of the oxide semiconductor, a first conductor and a second conductor electrically connected to the oxide semiconductor, a fourth insulator over the third insulator, a third conductor which is over the fourth insulator and at least part of which is between the first conductor and the second conductor, and a fifth insulator over the third conductor. The first insulator contains a halogen element.
1. A semiconductor device comprising:
a first conductor embedded in an opening in a first insulator;
a second insulator in contact with a top surface of the first conductor and a top surface of the first insulator;
a first oxide semiconductor over the second insulator;
a second oxide semiconductor over the first oxide semiconductor;
a third oxide semiconductor over the second oxide semiconductor;
a gate insulator over the third oxide semiconductor;
a second conductor over the gate insulator;
a source electrode and a drain electrode electrically connected to the third oxide semiconductor;
a third insulator over the source electrode and the drain electrode; and
a fourth insulator in contact with a top surface of the second conductor and a top surface of the third insulator,
wherein the gate insulator has a region interposed between the third insulator and the second conductor, and
wherein the third oxide semiconductor has a region in contact with the fourth insulator.
2. The semiconductor device according to claim 1 , wherein the third insulator contains fluorine.
3. The semiconductor device according to claim 1 , wherein the fourth insulator is a nitride insulating film or an aluminum oxide film.
4. The semiconductor device according to claim 1 , wherein the source electrode and the drain electrode cover side surfaces of the second oxide semiconductor.
5. A semiconductor device comprising:
a first conductor embedded in an opening in a first insulator;
a second insulator in contact with a top surface of the first conductor and a top surface of the first insulator;
a first oxide semiconductor over the second insulator;
a second oxide semiconductor over the first oxide semiconductor;
a third oxide semiconductor over the second oxide semiconductor;
a gate insulator over the third oxide semiconductor;
a second conductor over the gate insulator;
a source electrode and a drain electrode electrically connected to the third oxide semiconductor;
a third insulator over the source electrode and the drain electrode; and
a fourth insulator in contact with a top surface of the second conductor and a top surface of the third insulator,
wherein the gate insulator and the third oxide semiconductor have a region interposed between the third insulator and the second conductor.
6. The semiconductor device according to claim 5 , wherein the third insulator contains fluorine.
7. The semiconductor device according to claim 5 , wherein the fourth insulator is a nitride insulating film or an aluminum oxide film.
8. The semiconductor device according to claim 5 , wherein the source electrode and the drain electrode cover side surfaces of the second oxide semiconductor.