A Silicon Carbide Solid-State Photomultiplier (SiC-PM) was designed, fabricated and characterized for the first time. A die size of 3x3 mm2 has a 2x2 mm2 pixelated photosensitive area on it. The pixelated area consists of 16 sub-arrays of 0.5x0.5 mm2 with 64 pixels (60 μm pitch) in each sub-array. Each individual pixel has an integrated quenching resistor made of poly-silicon. Optical measurements of the SiC-PM were performed using fast UV LED with a wavelength of 300 nm demonstrating Geiger mode operation. Output signal waveforms measured at temperatures from 20°C to 200°C indicated temperature dependent time constants. The discrete nature of output signals indicated the capability of the SiC-PM to detect single photons from a faint UV light flux.
Photon counting detectors are used in many diverse applications and are well-suited to situations in which a weak signal
is present in a relatively benign background. Examples of successful system applications of photon-counting detectors
include ladar, bio-aerosol detection, communication, and low-light imaging. A variety of practical photon-counting
detectors have been developed employing materials and technologies that cover the waveband from deep ultraviolet
(UV) to the near-infrared. However, until recently, photoemissive detectors (photomultiplier tubes (PMTs) and their
variants) were the only viable technology for photon-counting in the deep UV region of the spectrum. While PMTs
exhibit extremely low dark count rates and large active area, they have other characteristics which make them
unsuitable for certain applications. The characteristics and performance limitations of PMTs that prevent their use in
some applications include bandwidth limitations, high bias voltages, sensitivity to magnetic fields, low quantum
efficiency, large volume and high cost.
Recently, DARPA has initiated a program called Deep UV Avalanche Photodiode (DUVAP) to develop semiconductor
alternatives to PMTs for use in the deep UV. The higher quantum efficiency of Geiger-mode avalanche photodiode
(GM-APD) detectors and the ability to fabricate arrays of individually-addressable detectors will open up new
applications in the deep UV. In this paper, we discuss the system design trades that must be considered in order to
successfully replace low-dark count, large-area PMTs with high-dark count, small-area GM-APD detectors. We also
discuss applications that will be enabled by the successful development of deep UV GM-APD arrays, and we present
preliminary performance data for recently fabricated silicon carbide GM-APD arrays.