Semiconductor structure and manufacturing method thereof
The present disclosure provides a semiconductor structure having a semiconductor layer; a gate with a conductive portion and a sidewall spacer; an interlayer dielectric (ILD) surrounding the sidewall spacer; and a nitrogen-containing protection layer, positioning at least on the top surface of the conductive portion of the gate. A top surface of the conductive portion and a top surface of the sidewall spacer are substantially coplanar. The nitrogen-containing protection layer is not covering the sidewall surface of the sidewall spacer. The present disclosure provides a method for manufacturing a semiconductor structure. The method includes forming a metal gate structure having a conductive portion and a sidewall spacer surrounded by a first ILD; forming a protection layer over the metal gate structure, and the protection layer is formed to cover at least the conductive portion of the metal gate structure; and forming a second ILD over the metal gate structure.
1. A semiconductor structure, comprising:
a semiconductor layer;
a plurality of gates, each comprising a conductive portion and a sidewall spacer, wherein a top surface of the conductive portion and a top surface of the sidewall spacer are substantially coplanar, and the plurality of gates are positioned over the semiconductor layer;
an interlayer dielectric (ILD) surrounding a sidewall surface of the sidewall spacer, positioning over the semiconductor layer;
a first nitrogen-containing protection layer, positioning at least on the top surface of the conductive portion of one of the gates, the first nitrogen-containing protection layer comprising a substantially vertical sidewall at one of the gates;
a second nitrogen-containing protection layer, positioning at least on the top surface of the conductive portion of another one of the gates, the second nitrogen-containing protection layer comprising a tapered sidewall at another one of the gates; and
a conductive plug simultaneously in contact with the sidewall surface and the top surface of the sidewall spacer;
wherein a full width of the first nitrogen-containing protection layer and a full width of the second nitrogen-containing protection layer are substantially equal to a full width of the conductive portion of each of the gates.
2. The semiconductor structure in claim 1 , wherein each of the first nitrogen-containing protection layer and the second nitrogen-containing protection layer comprises at least one of sulfur nitride, silicon nitride, silicon oxynitride, silicon carbonitride, or combinations thereof.
3. The semiconductor structure in claim 1 , wherein the first nitrogen-containing protection layer, the second nitrogen-containing protection layer and the sidewall spacer are made of same materials.
4. The semiconductor structure in claim 1 , wherein the semiconductor layer is a fin structure in a FinFET.
5. The semiconductor structure in claim 1 , wherein the top surface of the conductive portion is a substantial level plane.