Air Bridge Technology: A Comparison of Novel Interconnect Materials and Integration Schemes for Beyond 45 nm

The electronics industry, in a continual drive for improved integrated device performance, is seeking increasingly lower dielectric constants (k) of the insulators that are used as interlayer dielectric (ILD) for advanced logic interconnects. As the industry continually seeks a stepwise reduction of the “effective” dielectric constant (keff), simple extendibility, leads to the consideration of the highest performance possible, namely air bridge technology. In this paper we will discuss requirements, integration schemes and properties for a novel class of materials that has been developed as part of an advanced technology probe into air bridge architecture. We will compare and contrast these potential technology offerings with other existing dense and porous ILD integration options, and show that the choice is neither trivial nor obvious.