Low Si-OH ORMOCER®s for dielectrical and optical interconnection technology
ORMOCER®*s (inorganic-organic hybrid polymers) with low Si-OH content were synthesized by a new sol-gel route. Optimization of the sol-gel process parameters (catalyst, temperature etc.) was performed in order to achieve reproducible low cost materials which are photopatternable even in higher layer thicknesses up to 150 m within one step without cracking or delamination. The materials combine low losses in the NIR region (0.2 dB/cm at 1310 nm and 0.5 dB/cm at 1550 nm without fluorination!) with low dielectric constants (3.3 at 10 kHz). Beside the dielectric and optical properties the materials have a variety of additional advantages for interconnection technology: good wetting and adhesion on various substrates (e.g. glass, silicon and several polymers), low processing temperatures (postbake below 160°C), high thermal stability (up to 270°C) and a tunable refractive index. Details of chemical synthesis and characterization as well as photo-lithographic processing of OR MOCER® materials are presented.