Patent ID: 11935752
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A device comprising:
an interlayer dielectric (ILD) layer over a substrate;
a gate structure laterally surrounded by the ILD layer, wherein a top surface of the gate structure is lower than a top structure of the ILD layer;
a gate spacer extending along a sidewall of the gate structure to past the top surface of the gate structure; and
a dielectric cap over the gate structure and in contact with the gate spacer, wherein a concentration of nitrogen in the dielectric cap periodically varies from a center of a top of the dielectric cap to an edge of the dielectric cap, the dielectric cap comprises:
a first nitrogen-rich layer on and in contact with the gate structure;
a first oxygen-rich layer on and in contact with the first nitrogen-rich layer;
a second nitrogen-rich layer on and in contact with the first oxygen-rich layer; and
a second oxygen-rich layer on and in contact with the second nitrogen-rich layer.