Photonics chip patterning with multiple photoresist layers

Abstract

Structures for a photonics chip that include a cavity or groove and methods of forming same. The structure comprises a semiconductor substrate including a first opening, a back-end-of-line stack on the semiconductor substrate, and a dielectric layer on the back-end-of-line stack. The back-end-of-line stack includes a pad, and the dielectric layer includes a second opening that extends to the pad. The structure further comprises an electrical interconnect inside the second opening in the dielectric layer. The electrical interconnect includes a sidewall that is separated in a lateral direction from the dielectric layer by a gap.

Dependencies are inferred from the claim text.