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.