An isolator includes a first insulating portion, a first electrode provided in the first insulating portion, a second insulating portion provided on the first insulating portion and the first electrode, a third insulating portion provided on the second insulating portion, and a second electrode provided in the third insulating portion. The second insulating portion includes a plurality of first voids and a second void. The plurality of first voids are arranged in a first direction parallel to an interface between the first insulating portion and the second insulating portion. At least one of the first voids is provided under the second void.
1. An isolator, comprising:
a first insulating portion;
a first electrode provided in the first insulating portion;
a second insulating portion provided on the first insulating portion and the first electrode, the second insulating portion including a plurality of first voids and a second void, the plurality of first voids being arranged in a first direction parallel to an interface between the first insulating portion and the second insulating portion, the first voids being provided under the second void so that the second void is connected to four of the first voids;
a third insulating portion provided on the second insulating portion; and
a second electrode provided in the third insulating portion.
2. The isolator according to claim 1 , wherein
the second insulating portion includes:
a third insulating film including the plurality of first voids; and
a fourth insulating film including the second void,
the third insulating film is provided above the first insulating portion and the first electrode, and
the fourth insulating film is provided on the third insulating film.
3. The isolator according to claim 2 , wherein
the second insulating portion further includes a fifth insulating film provided between the first insulating portion and the third insulating film, and
the fifth insulating film includes a third void, the at least one of the first voids being provided above the third void, the third void having a same configuration as the second void and communicating with the at least one of the first voids.
4. The isolator according to claim 2 , wherein
the second insulating portion includes:
a sixth insulating film provided on the fourth insulating film; and
a seventh insulating film provided on the sixth insulating film, and
the seventh insulating film includes a portion embedded in the sixth insulating film.
5. The isolator according to claim 1 , wherein
the second insulating portion includes:
a third insulating film extending between the first insulating portion and the third insulating portion; and
a fourth insulating film extending between the third insulating film and the third insulating portion,
the third insulating film includes the plurality of first voids arranged in the first direction, and
the fourth insulating film includes a plurality of island-like regions surrounded with the second void.
6. The isolator according to claim 1 , wherein
the second insulating portion further includes a third void provided at a level between a level of the first void and a level of the second void in a third direction from the first insulating portion toward the third insulating portion,
the first to third voids each are rectangular in a cross section of the second insulating portion crossing the third direction, and
the third void is connected to the first and second voids at four corners of the rectangle of the third void.
7. An isolator, comprising:
a first insulating portion;
a first electrode provided in the first insulating portion;
a second insulating portion provided on the first insulating portion and the first electrode, the second insulating portion including a plurality of first voids and a second void, the plurality of first voids being arranged in a first direction parallel to an interface between the first insulating portion and the second insulating portion, at least one of the first voids being provided under the second void and being connected to the second void;
a third insulating portion provided on the second insulating portion;
a second electrode provided in the third insulating portion; and
a first insulating film provided between the second electrode and the second insulating portion, the first insulating film including a different material from a material of the second insulating portion.
8. The isolator according to claim 7 , wherein
the plurality of first voids extends in a second direction crossing the first direction, and
the second void extends in the first direction.
9. The isolator according to claim 7 , wherein
the first void and the second void are provided in slit configurations extending in a second direction crossing the first direction.
10. The isolator according to claim 7 , wherein
the second insulating portion includes:
a third insulating film including the plurality of first voids; and
a fourth insulating film including the second void,
the third insulating film is provided above the first insulating portion and the first electrode, and
the fourth insulating film is provided on the third insulating film.
11. The isolator according to claim 10 , wherein
the second insulating portion further includes a fifth insulating film provided between the first insulating portion and the third insulating film, and
the fifth insulating film includes a third void, the at least one of the first voids being provided above the third void, the third void having a same configuration as the second void and communicating with the at least one of the first voids.
12. The isolator according to claim 10 , wherein
the second insulating portion includes:
a sixth insulating film provided on the fourth insulating film; and
a seventh insulating film provided on the sixth insulating film, and
the seventh insulating film includes a portion embedded in the sixth insulating film.
13. An isolator, comprising:
a first insulating portion;
a first electrode provided in the first insulating portion;
a second insulating portion provided on the first insulating portion and the first electrode, the second insulating portion including a plurality of first voids and a second void, the plurality of first voids being arranged in a first direction parallel to an interface between the first insulating portion and the second insulating portion, at least one of the first voids being provided under the second void and being connected to the second void;
a third insulating portion provided on the second insulating portion; and
a second electrode provided in the third insulating portion, wherein the second insulating portion includes a second insulating film continuously provided between the first electrode and the plurality of first voids.
14. The isolator according to claim 13 , wherein
the plurality of first voids extends in a second direction crossing the first direction, and
the second void extends in the first direction.
15. The isolator according to claim 13 , wherein
the second insulating portion includes:
a third insulating film including the plurality of first voids; and
a fourth insulating film including the second void,
the third insulating film is provided above the first insulating portion and the first electrode, and
the fourth insulating film is provided on the third insulating film.
16. The isolator according to claim 15 , wherein
the second insulating portion further includes a fifth insulating film provided between the first insulating portion and the third insulating film, and
the fifth insulating film includes a third void, the at least one of the first voids being provided above the third void, the third void having a same configuration as the second void and communicating with the at least one of the first voids.
17. The isolator according to claim 15 , wherein
the second insulating portion includes:
a sixth insulating film provided on the fourth insulating film; and
a seventh insulating film provided on the sixth insulating film, and
the seventh insulating film includes a portion embedded in the sixth insulating film.
18. The isolator according to claim 13 , wherein
the first void and the second void are provided in slit configurations extending in a second direction crossing the first direction.