A semiconductor device includes a semiconductor body and a low K dielectric layer overlying the semiconductor body. A first portion of the low K dielectric layer comprises a dielectric material, and a second portion of the low K dielectric layer comprise an air gap, wherein the first portion and the second portion are laterally disposed with respect to one another. A method for forming a low K dielectric layer is also disclosed and includes forming a dielectric layer over a semiconductor body, forming a plurality of air gaps laterally disposed from one another in the dielectric layer, and forming a capping layer over the dielectric layer and air gaps.