Interconnect structure with reinforcing spacer and method for manufacturing the same

Abstract

A method for manufacturing an interconnect structure includes: forming a first dielectric layer; forming a mask; patterning the first dielectric layer through the mask to form a trench, an inner surface of the trench having two first portions opposite to each other along an X direction, two second portions opposite to each other along a Y direction, and a bottom portion; forming a second dielectric layer over the mask and the patterned first dielectric layer, and along an inner surface of the trench; etching the second dielectric layer by directing an etchant in a predetermined direction such that a first part of the second dielectric layer on the two first portions and the bottom portion is removed, and a second part of the second dielectric layer on the second portions of the trench remains and is formed into two reinforcing spacers; and forming a trench-filling element.