MIDDLE OF THE LINE HEATER AND METHODS

A semiconductor structure includes a semiconductor device (e.g., an e-fuse or photonic device) and a metallic heating element adjacent thereto. The heating element has a lower portion within a middle of the line (MOL) dielectric layer adjacent to the semiconductor device and an upper portion with a tapered top end that extends into a back end of the line (BEOL) dielectric layer. A method of forming the semiconductor structure includes forming a cavity such that it has both a lower section, which extends from a top surface of a MOL dielectric layer downward toward a semiconductor device, and an upper section, which extends from the top surface of the MOL dielectric layer upward and which is capped by an area of a BEOL dielectric layer having a concave bottom surface. A metallic fill material can then be deposited into the cavity (e.g., through via openings) to form the heating element.