Direct Radiation Detection Silicon Multiplier

There are several situations where radiation must be detected and imaged (e.g., in medical imaging, high energy physics, homeland security). We propose to develop an extremely sensitive direct radiation digital silicon photomultiplier array. In phase I, we will develop the individual avalanche detector pixel elements through simulation, fabrication, and testing. The pixels will be fabricated in our deep depletion complementary metal oxide semiconductor (CMOS) sensor technology based on a 0.18 μm mixed signal process. The starting material is a very high resistivity silicon wafer. After processing, the wafers are thinned, and a backside electrode is added. As a result, we can make a near 100% fill factor diode with a thick absorption region up to 400 μm suitable for direct detection of radiation. In phase II, we will design and fabricate a monolithic CMOS large area direct radiation detector based on an array of the avalanche detector pixels developed in phase I. This detector will consist of an array of optically isolated avalanche detector pixels with in-pixel digitization, bias, and quenching circuitry and an appropriate readout circuit. This near 100% fill factor pixel array will be suitable for direct radiation detection. While the imager is intended for direct radiation detection, it will also be extremely sensitive to broadband visible light (ultraviolet to near infrared). There are a range of commercial applications that stands to benefit from this high sensitivity broadband image sensor. • LIDAR & range detection - low cost solution for self-driving cars ; • Night vision – low cost replacement for the microchannel plate tube technology ; • Security cameras – eliminating or reducing the illumination needed to detect activity ; • Machine vision – high speed low light imaging for various purposes ; • Fluorescence Lifetime Imaging Microscopy (FLIM) ; • Optical tomography ; • Fiber optic communication