DIVOT-FREE PLANARIZATION DIELECTRIC LAYER FOR REPLACEMENT GATE

摘要

After formation of a silicon nitride gate spacer and a silicon nitride liner overlying a disposable gate structure, a dielectric material layer is deposited, which includes a dielectric material that is not prone to material loss during subsequent exposure to wet or dry etch chemicals employed to remove disposable gate materials in the disposable gate structure. The dielectric material can be a spin-on dielectric material or can be a dielectric metal oxide material. The dielectric material layer and the silicon nitride liner are planarized to provide a planarized dielectric surface in which the disposable gate materials are physically exposed. Surfaces of the planarized dielectric layer is not recessed relative to surfaces of the silicon nitride layer during removal of the disposable gate materials and prior to formation of replacement gate structures, thereby preventing formation of metallic stringers.

主权项

1. A method of forming a semiconductor structure comprising:
forming a disposable gate structure comprising at least a disposable gate material portion on a semiconductor substrate; forming a silicon nitride gate spacer on sidewalls of said disposable gate structure; forming a silicon nitride liner on said silicon nitride gate spacer and over said disposable gate structure; forming a planarization dielectric layer comprising an amorphous metal oxide on said silicon nitride liner; annealing said planarization dielectric layer to convert said amorphous metal oxide into a polycrystalline metal oxide; physically exposing a topmost surface of said disposable gate structure by planarizing said planarization dielectric layer and said silicon nitride liner; forming a gate cavity by removing said disposable gate structure, wherein topmost surfaces of said silicon nitride spacer, said silicon nitride liner, and said planarization dielectric layer are within a horizontal plane; and forming a replacement gate structure within said gate cavity.