Modelling and simulation for dielectric constant of aerogel

Aerogel exhibits several attractive features as an interconnect dielectric in ULSI, because of its ultralow dielectric constant ( ϵ eff=1∼4.2), high dielectric strength, and good gapfill capabilities. In this paper, a uniformly distributed pore structure model which shows a significant improvement compared with parallel and serial models is presented to simulate the ϵ eff of aerogel. An empirical relation between the ϵ eff of aerogel and its porosity is obtained. At the same time, the effect of porosity, pore shape, pore size, pore-size distribution and pore distribution on the ϵ eff of aerogel is determined. It is found that the porosity is a major factor which affects ϵ eff.