Large Area, Scalable UV Detectors Based on Silicon Carbide

State-of-the-art solid-state deep-ultraviolet photon detection devices (for light wavelengths less than 300 nanometers) are based on wide bandgap semiconductors, such as vertical SiC Geiger-Mode Avalanche Photodiodes (GM-APDs). Manufacturing vertical SiC GM-APDs requires a specialized process stack that precludes monolithic integration of readout electronics; this severely limits detector size and drives up the cost for large area detectors and arrays. Over the past three years, Ozark IC has developed UV photon-sensing applications with SiC CMOS technology. Using a new, patented SiC UV detector, Ozark IC is now able to integrate electronic circuitry with the UV detector to create UV pixels. All the advantages of pixel arrays ensue, including a large number of pixels (up to 28,000) and the ability to electronically “remove” defective detectors. This enables wafer-scale economics to be applied to the manufacture of large area UV detectors. Ozark IC has fabricated a large set of UV sensing test devices (that exhibit extremely high responsivity) and test circuits using SiC CMOS technology and proposes to re-examine this material for use as a Geiger-mode large area UV array. A wide selection of UV sensor devices will be evaluated at probe using bench top UV sources such as LEDs. Candidate devices will be packaged and retested. The packaged device will then be tested over the UV spectrum for photon-counting capability at Brookhaven National Labs. From these results, an optimized photon-counting device layout will be designed and applied to a large area array of detectors. The Phase I study will conclude with a large area detector design that is ready for fabrication in Phase II. In addition to its application to high energy physics, the anticipated public benefits of the proposed research begin with enabling next generation ultraviolet imaging sub-systems for weather satellites, machine vision, industrial controls, safety, and diagnostic/inspection systems. Deep-ultraviolet detection is of particular interest to semiconductor and scientific imaging markets, and applications in all temperature ranges, not just extreme temperatures.