Hybrid SiC Pixel Detector for Charged-Particle Beam Monitor

Abstract

We report on the hybrid SiC pixel detector for charged-particle beam monitors in high-energy physics experiments. To demonstrate comparable performances of the state-of-the-art Si pixel detectors, SiC pixel sensors with a die size of 25 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> were fabricated based on the p-n diode structure. We combined 12 × 12 diodes of a pixel size of 160 μm and 270 μm pitch with the dedicated readout ASIC by In/Au stud-bump technology. The front-end chip was designed in 0.35 μm CMOS technology, with consideration of a hybrid configuration. Each pixel circuit consists of a charge-sensitive amplifier and band-pass filter, optimized for the SiC sensor. The low noise performance achieved an equivalent noise charge of 55 ± 5e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–</sup> (rms). The spectrum of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">241</sup> Am shows an energy resolution of 1.72 keV (FWHM) at 17.8 keV γ-rays at room temperature. The obtained image with <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">90</sup> Sr is a proof of a single MIP detection capability with all pixels. Those results prospect a future application of the SiC pixel sensors to high-intensity proton extinction monitors in the COMET muon experiment at Japan Proton Accelerator Research Complex.