Patent ID: 9449921
Filing Date: 2016-09-20
CPC Classification: H01L

Claim Text:
1. A method of forming a contact structure, said method comprising: providing, from bottom to top, a base structure and a dielectric structure, wherein a conductive material portion is embedded in said base structure, and wherein a contact opening is located within said dielectric structure; forming a diffusion barrier portion within a lower portion of said contact opening and a first contact metal structure on said diffusion barrier portion, wherein a divot is present at an upper portion of said first contact metal structure, wherein forming said diffusion barrier portion within said lower portion of said contact opening and said first contact metal structure on said diffusion barrier portion comprises: depositing a contiguous layer of a diffusion barrier material within said contact opening and on said topmost surface of said dielectric structure; forming a first contact metal on said contiguous layer of said diffusion barrier material, wherein a void is present in said first contact metal; removing portions of said contiguous layer of said diffusion barrier material and said first contact metal that are present on said topmost surface of said dielectric structure; and recessing remaining portions of said diffusion barrier material and said first contact metal to provide said diffusion barrier portion and said first contact metal structure; forming a pair of spaced apart dielectric spacers within said contact opening and on a topmost surface of said diffusion barrier portion and a portion of a topmost surface of said first contact metal structure, wherein each dielectric spacer has a sidewall surface contacting a sidewall surface of said dielectric structure; and forming a second contact metal structure within said contact opening and between said pair of dielectric spacers, wherein a portion of said second contact metal structure completely fills said divot present in said first contact metal structure.