An air gap structure and formation method for substantially reducing the undesired capacitance between adjacent interconnects, metal lines or other features in an integrated circuit device is disclosed. The air gap extends above, and may also additionally extend below, the interconnects desired to be isolated thus minimizing fringing fields between the lines. The integrated air gap structure and formation method can be utilized in conjunction with a tungsten plug process. Also, multiple levels of the integrated air gap structure can be fabricated to accommodate multiple metal levels while always ensuring that physical dielectric layer support is provided to the device structure underlying the interconnects.