Patent ID: 11955376
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A semiconductor device, comprising:
a semiconductor substrate;
a dielectric structure arranged over the semiconductor substrate;
first and second metal vias disposed in the dielectric structure and spaced laterally apart from one another;
first and second metal lines disposed in the dielectric structure and having nearest neighboring sidewalls that are spaced laterally apart from one another by a portion of the dielectric structure, the first and second metal lines contacting upper portions of the first and second metal vias, respectively; and
first and second air gaps disposed in the portion of the dielectric structure, the first and second air gaps being proximate to the nearest neighboring sidewalls of the first and second metal lines, respectively, wherein a top surface of the first and second air gaps is below a top surface of the first and second metal lines;
a first metal cap layer disposed in a lowermost portion of the dielectric structure, the first metal cap layer having outermost sidewalls spaced apart by a first distance; and
a second metal cap layer disposed in an uppermost portion of the dielectric structure, the second metal cap layer having a metal composition that differs from that of the first and second metal lines.