Semiconductor transistor device including backside contact structure vertically between backside power rail and source/drain structure and method of forming thereof

Abstract

Provided is a method of manufacturing an integrated circuit device. The method includes forming a semiconductor device, wherein the semiconductor device has one or more source/drain structures, one or more channel structures and wherein the substrate is on a first side of the semiconductor device. The method also includes forming a back-end-of-line (BEOL) region and forming a bottle-neck shaped backside contact structure in the substrate and in contact with a first source/drain structure of the semiconductor device, wherein the bottle-neck shaped backside contact structure has a first side contacting the first source/drain structure, a second side contacting a backside power rail, and sidewalls extending from the first source/drain structure to the backside power rail; and wherein the backside contact structure has a first region having a positive slope and a second region, adjacent to the first region, having no slope.