Improvement of cohesion strength in ULK OSG materials by pore structure adjustment

Abstract

In this study cohesion strength in low-k dielectric films was enhanced by tuning the pore structure. The correlation between the average size of pores in ultra-low-k materials and cohesion energy was demonstrated by performing a 4-point bending test on multi-layer structures including TaN/Ta metal barrier. Spin-on organosilica films prepared with different templating surfactants were used to alleviate porosity-pore size coupling, which revealed the particular role of pore size with respect to material toughness. The paper also discusses aspects of material design at precursor level.