Parylene Copolymers

Abstract

AbstractImprovements in the properties of Parylene may enable their use in high performance integrated circuits. Parylenes are a class of polymers formed by chemical vapor deposition which nearly meet the high standards of the low-k triumvirate, namely, 1) adhesion, particularly to SiO2, 2) thermal stability above 400 Celsius, and 3) permittivity less than 2.7. Parylene-N has been incorporated into both aluminum-1 and copper-2 based metallization schemes, however, improvements in the adhesion and thermal stability are still needed to simplify and increase the robustness of the integration schemes. Additionally, a reduction in the permittivity would be beneficial from both device performance and extendibility points-of-view. We have synthesized various Parylene-N-based copolymers with improved adhesion, thermal stability, and permittivity. We discovered that a copolymer of tetravinyl-tetramethyl-cyclotetrasiloxane and Parylene-N has a permittivity of close to 2.1 and both the adhesion to SiQ2 and thermal stability are measurably improved compared to the homopolymer.