Flexible films derived from PIM-1 with ultralow dielectric constants

Abstract High hydrophobicity, non-polar structure and large pore volume are among the main criteria demanded breakthrough when designing or selecting materials with ultralow dielectric constants of k. Herein we proved the feasibility of PIM-1 films, a constitutive porous polymer with high free volume, as a rising ultra-low-k material in the field of microelectronics. An ultrathin PIM-1 film of approximate 60 nm in thickness was easily obtained by the spin-coating approach. Thermal treatment on the PIM-1 film (denoted as sPIM-1) enhanced its dielectric performance and the incorporation of cyanopropyltriethoxysilane (CPTES) to sPIM-1 improved the mechanical strength of the film significantly. The sPIM-1 films exhibited an ultralow dielectric constant (k = 1.5 at 10 kHz), substantial mechanical strength, and ability to withstand high humidity (soaking in water for 30 min) without losing their dielectric properties. The easy curing process and extremely stable performances even under the harsh conditions of practical application make it one of the most competitive candidates of low dielectric materials at present.