Abstract: 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 either damascene or conventional integrated circuit metallization schemes. 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.

Abstract: The present invention provides a method for forming an antifuse via structure. The antifuse via structures comprising a substrate that having a first conductive wire therein. Then, a first dielectric layer is formed on the substrate, and a photoresist layer is formed on the first dielectric layer. Next, an etching process is performed to etch the first dielectric layer to form a via open in the first dielectric layer. Then, a first conductive layer is deposited to fill the via open and performing a polishing process to form a conductive plug, wherein the conductive plug is on the first conductive wire. Next, a buffer layer deposited on the partial first dielectric layer and on the surface of conductive plug. Then, another polishing process is performed to the buffer layer to expose the portion of the conductive plug. Thereafter, a first electrode of capacitor is deposited on the buffer layer.