Wafer-bonded silicon gamma-ray detectors

High-resistivity silicon wafers processed for use as gamma-ray detectors are wafer bonded together at low temperatures to produce thicker detectors. The bonding process allows performance similar to an unbonded detector and preserves the high resistivity and long minority carrier lifetimes of the individual wafers. Ultimately, this process will allow thicker detectors than are currently available. This will yield more efficient silicon detectors that are operational at room temperature and are useful for low energy x-ray detection as well as for sensitive Compton imagers. New results from wafer-bonded silicon detectors showing good gamma-ray resolution (4.5 keV FWHM) and performance similar to an unbonded detector (verified with both alpha particles and gamma rays) is presented. A technique to mitigate void formation at the bond interface, maintain material quality, and improve performance of a bonded detector is presented.