Integrated circuit chips comprising forksheet devices connected with buried power rails

Abstract

Integrated circuit chips and method for making integrated circuit chips are provided. The method includes providing a semiconductor substrate, forming a device layer including a forksheet device on the substrate and providing the substrate with a substrate part of a dielectric wall of the forksheet device, a first shallow trench isolation and a second shallow trench isolation. The method also includes contacting a source or drain contact and extending into the substrate between the first shallow trench isolation and the dielectric wall, then removing the substrate material so as to expose an end of the dielectric wall, the first surface, and the second surface, then obtaining a first spacer and a second spacer, so as to obtain a trench, wherein the end of the dielectric wall is exposed to the trench, then depositing an electrically insulating material in the trench so as to form an extension.