AEGIS: A Pixel-array Readout IC for Gamma-ray Imaging

DESCRIPTION (provided by applicant): CdZnTe arrays are promising detectors for improving nuclear medicine imaging, but existing CdZnTe cameras have limited spatial resolution and small numbers of pixels (space bandwidth product = SpBW). We show that major performance improvements will require high SpBW (>10A5) and small pixels (high resolution). The best approach to obtaining high SpBW detectors is to make many hybrid detector rays composed of a pixellated slab of CdZnTe indium bump bonded to a readout circuit, but a new highperformance readout circuit is required. The University of Arizona Center for Gamma-Ray Imaging (CGRI) and Augustine Engineering have actively collaborated in developing such hybrid detector arrays for use in biomedical gamma ray imaging. We propose to design and build a 64 x 64 readout (AEGIS) in Phase II, which will support the development of high performance clinical semi-conductor cameras. AEGIS will be an event-driven readout with a shaper-amplifier unit cell, active leakage current compensation and 310 um pitch for excellent spatial resolution. In Phase I we will design, fabricate and test an 8 x 8 prototype AEGIS and then make 8x8 hybrid CdZnTe detectors to verify feasibility.