Manufacturing method of semiconductor device
A semiconductor device with a small variation in transistor characteristics can be provided. A step of forming an opening in a structure body including an oxide semiconductor device to reach the oxide semiconductor device, a step of embedding a first conductor in the opening, a step of forming a second conductor in contact with a top surface of the first conductor, a step of forming a first barrier insulating film by a sputtering method to cover the structure body, the first conductor, and the second conductor, and a step of forming a second barrier insulating film over the first barrier insulating film by an ALD method are included. The first barrier insulating film and the second barrier insulating film each have a function of inhibiting hydrogen diffusion.
1 . A method for manufacturing a semiconductor device comprising the steps of:
forming an opening in a structure body comprising an oxide semiconductor device to reach the oxide semiconductor device;
embedding a first conductor in the opening;
forming a second conductor in contact with a top surface of the first conductor;
forming a first barrier insulating film by a sputtering method to cover the structure body, the first conductor, and the second conductor; and
forming a second barrier insulating film over the first barrier insulating film by an ALD method,
wherein a bottom surface of the first barrier insulating film faces the oxide semiconductor device,
wherein the first barrier insulating film is in contact with a top surface and a side surface of the second conductor,
wherein a thickness of the first barrier insulating film is larger than a thickness of the second barrier insulating film, and
wherein the first barrier insulating film and the second barrier insulating film are each configured to inhibit hydrogen diffusion.
2 . The method for manufacturing a semiconductor device according to claim 1 , wherein the first barrier insulating film comprises silicon nitride.
3 . The method for manufacturing a semiconductor device according to claim 1 , wherein the second barrier insulating film comprises silicon nitride.
4 . The method for manufacturing a semiconductor device according to claim 1 , wherein a hydrogen concentration of the first barrier insulating film is lower than a hydrogen concentration of the second barrier insulating film.
5 . The method for manufacturing a semiconductor device according to claim 1 , wherein the second barrier insulating film is formed by a PEALD method.
6 . The method for manufacturing a semiconductor device according to claim 1 , wherein a precursor not containing an organic substance is used for the formation of the second barrier insulating film.
7 . A method for manufacturing a semiconductor device comprising the steps of:
forming an opening in a structure body comprising an oxide semiconductor device to reach the oxide semiconductor device;
embedding a first conductor in the opening;
forming a second conductor in contact with a top surface of the first conductor;
forming a first barrier insulating film by a sputtering method to cover the structure body, the first conductor, and the second conductor;
forming a second barrier insulating film over the first barrier insulating film by an ALD method;
forming a third barrier insulating film by an ALD method; and
forming a fourth barrier insulating film over the third barrier insulating film by a sputtering method,
wherein a bottom surface of the first barrier insulating film faces the oxide semiconductor device,
wherein the first barrier insulating film is in contact with a top surface and a side surface of the second conductor,
wherein a thickness of the first barrier insulating film is larger than a thickness of the second barrier insulating film, and
wherein a top surface of the fourth barrier insulating film comprises a region facing the bottom surface of the first barrier insulating film with the oxide semiconductor device sandwiched therebetween,
wherein the formation of the third barrier insulating film and the formation of the fourth barrier insulating film are performed before the step of forming the structure body, and
wherein the first barrier insulating film, the second barrier insulating film, the third barrier insulating film, and the fourth barrier insulating film are each configured to inhibit hydrogen diffusion.
8 . The method for manufacturing a semiconductor device according to claim 7 , wherein the first barrier insulating film comprises silicon nitride.
9 . The method for manufacturing a semiconductor device according to claim 7 , wherein the second barrier insulating film comprises silicon nitride.
10 . The method for manufacturing a semiconductor device according to claim 7 , wherein a hydrogen concentration of the first barrier insulating film is lower than a hydrogen concentration of the second barrier insulating film.
11 . The method for manufacturing a semiconductor device according to claim 7 , wherein the second barrier insulating film is formed by a PEALD method.
12 . The method for manufacturing a semiconductor device according to claim 7 , wherein a precursor not containing an organic substance is used for the formation of the second barrier insulating film.
13 . The method for manufacturing a semiconductor device according to claim 7 , wherein the third barrier insulating film comprises silicon nitride.
14 . The method for manufacturing a semiconductor device according to claim 7 , wherein the fourth barrier insulating film comprises silicon nitride.
15 . The method for manufacturing a semiconductor device according to claim 7 , wherein a hydrogen concentration of the fourth barrier insulating film is lower than a hydrogen concentration of the third barrier insulating film.
16 . The method for manufacturing a semiconductor device according to claim 7 , wherein the third barrier insulating film is formed by a PEALD method.
17 . The method for manufacturing a semiconductor device according to claim 7 , wherein a precursor not containing an organic substance is used for the formation of the third barrier insulating film.
18 . The method for manufacturing a semiconductor device according to claim 7 , wherein an oxide semiconductor film included in the oxide semiconductor device is formed by a sputtering method using a target comprising one or more selected from In, Ga, and Zn.
19 . The method for manufacturing a semiconductor device according to claim 1 , wherein an oxide semiconductor film included in the oxide semiconductor device comprises an indium oxide.