AIR GAP CONTACT FORMATION FOR REDUCING PARASITIC CAPACITANCE

摘要

A functional gate structure is located on a surface of a semiconductor material portion and including a U-shaped gate dielectric portion and a gate conductor portion. A source region is located on one side of the functional gate structure, and a drain region is located on another side of the functional gate structure. The source region and drain region both have a topmost surface that is above a topmost surface of the semiconductor material portion and another surface that touches a portion of the U-shaped gate dielectric. A contact structure is located on the topmost surface of the source region and/or the drain region. A middle-of-the-line air gap contact is located between the contact structure and the functional gate structure and above at least one of the source region and the drain region. The middle-of-the-line air gap contact is sealed by a portion of a conformal dielectric material.

主权项

1. A semiconductor structure comprising:
a functional gate structure located on a surface of a semiconductor material portion and including a U-shaped gate dielectric portion and a gate conductor portion; a source region located on one side of the functional gate structure, wherein said source region has a topmost surface that is above a topmost surface of said semiconductor material portion and another surface that touches a portion of said U-shaped gate dielectric; a drain region located on another side of the functional gate structure, said drain region has a topmost surface that is above a topmost surface of said semiconductor material portion and another surface that touches a portion of said U-shaped gate dielectric; a contact structure located on said topmost surface of said at least one of said source region and said drain region; a middle-of-the-line air gap contact located between said contact structure and said functional gate structure and above at least one of said source region and said drain region, wherein said middle-of-the-line air gap contact is sealed by a portion of a conformal dielectric material; and a second functional gate structure comprising a second U-shaped gate dielectric portion and a second gate conductor portion and located adjacent said functional gate structure, wherein a second source region is located on one side of said functional gate structure and a second drain region is located on another side of said second functional gate structure, wherein said second source region is merged with said source region of said functional gate structure and wherein said contact structure and said middle-of-the line air gap contact are located above said merged source regions.