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 method of forming a semiconductor structure, said method comprising:
providing a sacrificial insulator structure on a surface of a semiconductor material portion; epitaxially growing a source region on one side of the sacrificial insulator structure and a drain region on another side of the sacrificial insulator structure, wherein both said source region and said drain region have a topmost surface that is above a topmost surface of said semiconductor material portion; replacing said sacrificial insulator structure with a functional gate structure, said functional gate structure comprising a U-shaped gate dielectric portion and a gate conductor portion, and wherein another surface of both said source region and said drain regions contacts a portion of said U-shaped gate dielectric portion; forming a sacrificial contact material portion within a contact opening and along a vertical sidewall of said functional gate structure; forming a contact structure on said topmost surface of at least one of said source region and said drain region; removing said sacrificial contact material portion; and forming a middle-of the-line air gap contact within a portion of a volume previously occupied by said sacrificial contact material portion.