Semiconductor device and manufacturing method of the same
To improve the electrical characteristics of a semiconductor device including an oxide semiconductor, and to provide a highly reliable semiconductor device with a small variation in electrical characteristics. The semiconductor device includes a first insulating film, a first barrier film over the first insulating film, a second insulating film over the first barrier film, and a first transistor including a first oxide semiconductor film over the second insulating film. The amount of hydrogen molecules released from the first insulating film at a given temperature higher than or equal to 400° C., which is measured by thermal desorption spectroscopy, is less than or equal to 130% of the amount of released hydrogen molecules at 300° C. The second insulating film includes a region containing oxygen at a higher proportion than oxygen in the stoichiometric composition.
1. A method for manufacturing a semiconductor device, comprising the steps of:
forming a first transistor;
performing a first heat treatment after forming the first transistor;
forming a first insulating film over the first transistor;
performing a second heat treatment after forming the first insulating film;
forming a first barrier film over the first insulating film after performing the second heat treatment;
forming a second insulating film over the first barrier film;
forming an opening in the second insulating film, the first barrier film, and the first insulating film; and
forming a second transistor comprising an oxide semiconductor film comprising a channel formation region, the second transistor being over the second insulating film and electrically connected to the first transistor through the opening.
2. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein a temperature of the second heat treatment is higher than that of the first heat treatment.
3. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein the first transistor is formed by using a semiconductor substrate.
4. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein the second heat treatment is performed for less than or equal to 10 hours at a temperature higher than or equal to 450° C. and lower than 650° C.
5. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein the first barrier film is loaned by a DC sputtering method.
6. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein a second barrier film is formed over the second transistor.
7. The method for manufacturing a semiconductor device, according to claim 6 ,
wherein the second barrier film is formed by a DC sputtering method.
8. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein after the first transistor is formed, a third insulating film containing hydrogen is formed before the first heat treatment.
9. A method for manufacturing a semiconductor device, comprising the steps of:
forming a first transistor;
performing a first heat treatment after forming the first transistor;
forming a first insulating film over the first transistor;
forming a first barrier film over the first insulating film;
forming a second insulating film over the first barrier film;
forming an opening in the second insulating film, the first barrier film, and the first insulating film;
performing a second heat treatment after forming the opening; and
forming a second transistor comprising an oxide semiconductor film comprising a channel formation region, the second transistor being over the second insulating film and electrically connected to the first transistor through the opening.
10. The method for manufacturing a semiconductor device, according to claim 9 ,
wherein a temperature of the second heat treatment is higher than that of the first heat treatment.
11. The method for manufacturing a semiconductor device, according to claim 9 ,
wherein the first transistor is formed by using a semiconductor substrate.
12. The method for manufacturing a semiconductor device, according to claim 9
wherein the second heat treatment is performed for less than or equal to 10 hours at a temperature higher than or equal to 450° C. and lower than 650° C.
13. The method for manufacturing a semiconductor device, according to claim 9 ,
wherein the first barrier film is formed by a DC sputtering method.
14. The method for manufacturing a semiconductor device, according to claim 9 ,
wherein a second barrier film is formed over the second transistor.
15. The method for manufacturing a semiconductor device, according to claim 14 ,
wherein the second barrier film is formed by a DC sputtering method.
16. The method for manufacturing a semiconductor device, according to claim 9 ,
wherein after the first transistor is formed, a third insulating film containing hydrogen is formed before the first heat treatment.