Reliability aspects of a radiation detector fabricated by post-processing a standard CMOS chip

This paper describes various reliability concerns of the newly developed INGRID detector. This radiation detector is fabricated by waferscale CMOS post-processing; fresh detectors show excellent performance. Since the microsystems will be used unpackaged they are susceptible to all kinds of environmental conditions. The device passed tests of micro-ESD, radiation hardness, dielectric strength; but humidity tests show one weakness of SU-8 as a structural material. Already after 1 day of exposure to a humid condition the structural integrity, as measured by a shear stress test, is dramatically lowered. Dry storage of these devices is therefore a necessity. KMPR photoresist shows promising results as an alternative structural material.