Abstract: The present disclosure provides an interconnect structure, including a first metal line, a second metal line spaced away from the first metal line, a conductive contact over the first metal line, including a first portion, a second portion over the first portion, wherein a bottom width of the second portion is greater than a top width of the first portion, wherein a shortest distance between the second portion and the second metal line is in a range from 50 Angstrom to 200 Angstrom, and a third portion over the second portion, wherein a bottom width of the third portion is greater than a top width of the second portion, the entire first portion and the entire second portion are under a coverage of a vertical projection area of the third portion, a first layer, and a second layer over the first layer.

Abstract: A capacitive biosensor is provided. The capacitive biosensor includes: a transistor, an interconnect structure on the transistor, and a passivation layer on the interconnect structure. The interconnect structure includes a first metal structure on the transistor, a second metal structure on the first metal structure, and a third metal structure on the second metal structure. The third metal structure includes a first conductive layer, a second conductive layer, and a third conductive layer that are sequentially stacked. The passivation has an opening exposing a portion of the third metal structure. The capacitive biosensor further includes a sensing region on the interconnect structure. The sensing region includes a first sensing electrode and a second sensing electrode. The first sensing electrode is formed of the third conductive layer, and the second sensing electrode is disposed on the passivation layer.

Abstract: Photolithography overlay errors are a source of patterning defects, which contribute to low wafer yield. An interconnect formation process that employs a patterning photolithography/etch process with self-aligned interconnects is disclosed herein. The interconnection formation process, among other things, improves a photolithography overlay (OVL) margin since alignment is accomplished on a wider pattern. In addition, the patterning photolithography/etch process supports multi-metal gap fill and low-k dielectric formation with voids.