Semiconductor device structure with a fine pattern and method for forming the same
The present application discloses a semiconductor device structure and a method for forming the same. The method includes forming a pillar over a substrate, forming a first ring structure over a sidewall of the pillar, removing the pillar to form a first opening surrounded by the first ring structure, forming a second ring structure in the first opening, forming a third ring structure surrounding the first ring structure after the first opening is formed, and removing the first ring structure to form a gap between the second and third ring structures. A semiconductor device structure includes a dielectric layer over a substrate, a first ring structure over the dielectric layer, and a second ring structure over the dielectric layer and surrounding the first ring structure, wherein the first and the second ring structures have a first common center.
1. A method for forming a semiconductor device structure, comprising:
forming a pillar over a substrate;
forming a first ring structure over a sidewall of the pillar;
removing the pillar to form a first opening surrounded by the first ring structure;
forming a dielectric layer over a top surface of the substrate and a top surface of the first ring structure;
forming a second ring structure in the first opening;
forming a third ring structure surrounding the first ring structure after the first opening is formed; and
removing the first ring structure to form a gap between the second ring structure and the third ring structure;
wherein a top surface of the dielectric layer is higher than top surfaces of the second ring structure and the third ring structure before the first ring structure is removed.
2. The method for forming a semiconductor device structure of claim 1 , wherein the first ring structure is in direct contact with the second ring structure, and a width of the first ring structure is substantially the same as a width of the second ring structure.
3. The method for forming a semiconductor device structure of claim 1 , wherein the first ring structure is in direct contact with the third ring structure, the second ring structure and the third ring structure are simultaneously formed, and a width of the second ring structure is substantially the same as a width of the third ring structure.
4. The method for forming a semiconductor device structure of claim 1 , wherein a width of the pillar is greater than about three times a width of the first ring structure.
5. The method for forming a semiconductor device structure of claim 1 , wherein the second ring structure and the third ring structure are formed over the dielectric layer, and a material of the dielectric layer is different from a material of the second ring structure and a material of the third ring structure.
6. The method for forming a semiconductor device structure of claim 1 , wherein a second opening is formed in the first opening after the second ring structure is formed, the second opening is surrounded by the second ring structure, and a width of the first ring structure is substantially the same as a width of the second opening.
7. A method for forming a semiconductor device structure, comprising:
forming a first pillar over a substrate;
forming a first ring structure surrounding the first pillar, wherein a width of the first pillar is greater than a width of the first ring structure;
removing the first pillar after the first ring structure is formed;
forming a dielectric layer over a top surface of the substrate after the first pillar is removed;
forming a second ring structure and a third ring structure over the dielectric layer, wherein the second ring structure is surrounded by the first ring structure, and the second ring structure is surrounded by the third ring structure; and
removing the first ring structure and a portion of the dielectric layer left uncovered by the second ring structure and the third ring structure.
8. The method for forming a semiconductor device structure of claim 7 , wherein a portion of the dielectric layer is formed over the first ring structure, and a top surface of the portion of the dielectric layer is higher than a top surface of the second ring structure and a top surface of the third ring structure.
9. The method for forming a semiconductor device structure of claim 7 , wherein the second ring structure is in direct contact with an inner sidewall of the first ring structure, and the third ring structure is in direct contact with an outer sidewall of the first ring structure.
10. The method for forming a semiconductor device structure of claim 7 , wherein the second ring structure and the third ring structure are separated by substantially the same distance.
11. The method for forming a semiconductor device structure of claim 7 , wherein bottom surfaces of the second ring structure and the third ring structure are higher than a bottom surface of the first ring structure.
12. The method for forming a semiconductor device structure of claim 7 , further comprising:
forming a second pillar over the substrate;
forming a fourth ring structure surrounding the second pillar;
removing the second pillar; and
forming a fifth ring structure lining an inner wall of the fourth ring structure and a sixth ring structure surrounding the fourth ring structure, wherein a distance between the third ring structure and the sixth ring structure is substantially the same as a width of the first ring structure and a width of the third ring structure.