Air gap technology by selective ozone/TEOS deposition

A technology for fabrication of air gaps is presented which is based upon selective ozone/TEOS deposition of oxide. Due to the isotropic growth direction of this process, some disadvantages of the more common approaches by nonconformal CVD processes can be avoided. It is demonstrated that air gap technology has the potential to reduce the capacitance between adjacent metal lines roughly by a factor of 2 compared to full structures without air gaps.