Photopatternable hybrid inorganic-organic polymers with negative resist behaviour have been developed and tested for evaluation in optical and electrical interconnection technology. They are composed of inorganic oxidic structures cross-linked or substituted by organic groups. The synthesis starts from organosilane precursors reacted by sol-gel-processing in combination with organic crosslinking of polymerisable organic functions. As a result of these functionalities the properties of the ORMOCER®s are adjusted to the particular applications. Systematic variation of composition combined with adaptation to micro system technology allows great flexibility in processing. The main features of these materials are:
• Combined use as dielectric and passivation layers in electrical systems and devices as well as core and cladding for optical applications enables e/o applications with high integration levels.
• Postbaking at moderate temperatures (120 - 170 °C) enables processing on low-cost substrates such as FR-4 (a glass-fibre reinforced epoxy-polymer).
• Easily adaptable to thin film technology: spin-on with planarisation > 90 %, via diameters down to 20 μm and high aspect ratio for optical waveguides have been achieved.
Synthesis, modification of the resins towards technological needs, their thin film technology and the resulting demonstrators will be discussed.