Dielectric anisotropy in the integration of Cu-SiLK (TM) system

Abstract

As device density and performance continue to improve, low dielectric constant (k) materials are needed for interlevel dielectric (ILD) applications. The dielectric anisotropy of polymers with low k is an important property to consider for developing ILD. This is on-going research on the integration aspects of Cu-SiLK(TM) system. In this study, the dielectric anisotropy of SiLK polymer was evaluated with two test structures: the metal-insulator-metal (MIM) parallel capacitor structure for the out-of-phase dielectric constant (k(perpendicular to)) and comb-and-serpentine interdigitated structure for the in-plane dielectric constant (k(parallel to)). A k(perpendicular to) of 2.65, a k(parallel to) of 2.75, and a dielectric anisotropy of 3.77% were obtained for SiLK. However, SiLK exhibits larger leakage current as compared to amorphous SiO2 films. The reliability issue on the integration of Cu-SiLK is discussed. (C) 2007 Elsevier B.V. All rights reserved.