| 主权项 |
1. A method for forming contact vias, comprising:
providing a substrate comprising a plurality of contact structures embedded in a first dielectric layer, wherein the contacts abut an upper surface of the first dielectric layer; providing a second dielectric layer on the upper surface of the first dielectric layer; providing contact vias in the second dielectric layer by patterning the second dielectric layer at least at positions corresponding to the contact structures; providing a hardmask layer on top of the second dielectric layer; patterning the hardmask layer to thereby remove a portion of the hardmask layer, thereby leaving at least an upper portion of the hardmask layer at positions where no vias in the second dielectric layer are to be formed; providing a patterned planarizing template layer on top of the patterned hardmask layer, and on the second dielectric layer if and where the hardmask layer is completely removed, wherein the patterned template layer includes a set of openings, wherein the set of openings are evenly distributed within the template layer and comprise a limited number of subsets of openings of identical size, and wherein at least some of the openings correspond to the positions of the contact structures; performing a direct self assembly (DSA) process that includes:
providing a predetermined Block Copolymer (BCP) material in all of the openings of the template layer,inducing polymer separation of the BCP in the openings, andremoving of a first component of the BCP in the openings, wherein the patterned template layer and a second component of the BCP define a pattern comprising DSA openings, and wherein the DSA openings are located at positions corresponding to the contact structures; and etching the contact vias in the second dielectric layer, using at least the second DSA component as a mask. |
