Optical, electrical and structural properties of spin-on MSQ low-k dielectrics over a wide temperature range

Looking onto application of low-k and ultra low-k materials within FEOL, high temperature load is one of the major challenges. But also temperature ranges below standard curing conditions are of special interest, e.g. for integration of transparent low-k materials into optical devices due to their small refractive index. In this work the development of the optical, electrical and structural properties of two spin-on MSQ low-k dielectrics over a low-temperature range has been investigated. Incorporation of porosity due to porogen removal for LK2000 causes a different behaviour of the electrical and optical parameters compared to ACCUGLASS (TM) within the low-temperature range. Both materials show unstable properties which normalize by getting closer to the standard curing conditions. Hydrophobizity of the surfaces is developing at curing temperatures of 400 degrees C and higher, what agrees to the lowering of the leakage current density. Optical, electrical and structural parameters fluctuate very sensitive on changing the curing temperature, so usage of those materials within a low-temperature range requires a very stable curing process to achieve reproducible material properties.