Benzocyclobutene (DVS-BCB) polymer as an interlayer dielectric (ILD) material

Abstract

Polymer films of DVS-BCB (CYCLOTENE TM 5021) exhibit a combination of material and processing properties which make them an attractive low k interlayer dielectric (ILD) material for integration into IC manufacturing processes. Key DVS-BCB film properties include isotropic dielectric constant (2.65 @ 1 MHz); equilibrium moisture absorption (< 0.2% @ 25°C and 81% RH); high purity (< 10 ppb individual metals concentrations); T g > 350°C; low alpha-particle emission rates. The DVS-BCB films are easily produced using simple resist spin track equipment and are subsequently cured without generation of corrosive or volatile by-products under anaerobic conditions (less than 100 ppm oxygen). Films are completely cured for typical processing conditions at 250°C for 1 h or as rapidly as 30 s at 325°C. DVS-BCB has been demonstrated to fill 0.20 μm gaps at 5:1 aspect ratios. Fully cured films exhibit greater than 95% degree-of-planarization for isolated feature widths of 20 μm and less; 80% for widths between 20 μm and 100 μm. Currently, the acceptance of DS-BBC is challenged by today's thermal requirements of greater than 400°C for CD-W via/plug and post device/contact anneals. The development of moderate temperature metal deposition processes and reduced final device anneal temperatures would enable implementation of DS-BBC as an LID material with the realization of its low dielectric constant, excellent gap-fill and other attractive features.