Patent ID: 11935781
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  B | IPC H

Claim 0:
1. A method of forming a semiconductor device, the method comprising:
etching a recess in a substrate, wherein the substrate comprises a first material;
forming a plug in the recess in the substrate, wherein the plug comprises a second material different than the first material;
forming an epitaxial structure over the plug;
forming a gate structure on a first side of the substrate adjacent epitaxial structure;
removing at least a portion of a backside of the substrate to expose the plug;
forming a dielectric layer over the plug, the dielectric layer having an air gap therein;
removing the plug to form a backside via opening through the dielectric layer; and
forming a backside via in the backside via opening, wherein the backside via is electrically coupled to the epitaxial structure.