Here is the abstract you requested from the IMAPS_2012 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Reliability Study of Reference Semiconductor Encapsulation Materials for Biocompatible Packaging|
|Keywords: implant, biocompatible packaging, encapsulation|
|Materials are the key components when developing a biocompatible packaging process for implantable electronic systems. To secure a reliable performance of the chip in such a package, its encapsulation has to be considered up-front in the wafer-level integration scheme. A differentiation of two main material types can be made: 1) Insulating or passive materials functioning as a bi-directional diffusion barrier preventing body liquids to leak into the package causing systems malfunction due to possible materials corrosion and 2) Conductive or active materials as diffusion barrier, e.g. against copper diffusion or as direct external contacts and responsible for electrical performance of the system. This study is investigating the properties of two insulating and widely in the semiconductor industry used materials the nitride and the oxide. Both material types are deposited in a PVD system using different temperatures; 400°C for CMOS compatibility and 200°C for wafer back side integration when a temporary carrier system is used. The biocompatibility results for these materials using cell lines and primary cells are promising, showing vital cell growth. However, for the long term application, the results for oxide layers show hydration effects followed by material degradation where the nitride layers clearly show corrosion and are even etched when elevated temperatures are applied. This fact is surprising since nitride layers are widely used as a humidity barrier for various chip types but obviously not suitable for a direct contact with liquids. Various analysis methods using e.g. Fourier Transform Spectroscopy or mass measurements substantiate this thesis.|