A New Ultra-Low K ILD Material Based on Organic-Inorganic Hybrid Resins

A ULK material based on a siloxane resin has been developed that can be processed using spin-coating and thermal cure to yield porous low-k films. The chemical bonds between the resin and porogen groups prevent the phase separation of the porogen from the resin during curing and lead to extremely small pores. The highly hydrophobic thin films made from this material displayed dielectric constant of 1.8, breakdown voltage of 4 MV/cm, a cohesive strength > 60 MPa, excellent crack resistance, and an average pore size of 2.2 nm by Positron Annihilation Lifetime Spectroscopy (PALS) and 2.5-3.0 nm by Ellipsometric Porosimetry (EP). In this paper, our strategy for designing low-k materials, the material properties and initial integration results for this new material will be discussed.