Silacyclobutane-functionalized cyclosiloxanes as photoactive precursors for high thermal stability, low dielectric constant and low dielectric loss polymers

Low dielectric photoactive materials have significant potential as components in future microelectronics. Although a number of photosensitive groups have been used to construct photopatternable materials, it remains challenging to introduce these groups into polymer chains via facile yet controlled polymerization techniques. The present work demonstrates the synthesis of a new class of photoactive cyclosiloxane monomers having hybrid siloxane-carbosilane main chains. These compounds can be cured by applying ultraviolet radiation and heat to promote the reaction of the silacyclobutene units and form hyper-cross-linked cyclosiloxanes. The cured resins show high thermal stability (with T-5% values in the range of 460-550 degrees C), low dielectric constants (2.36-2.76 at 10 MHz) and low dielectric losses (10(-3) at 10 MHz). Thus, these polymers could possibly be used as high-performance dielectric materials.