Hybrid SiC Pixel Detector for Charged-Particle Beam Monitor

We report on the hybrid silicon carbide (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(2) were fabricated based on the p-n diode structure. We combined 12 x 12 diodes of a pixel size of 160 and 270 mu m pitches with the dedicated readout application-specific integrated circuit (ASIC) by indium and gold (In/Au) stud-bump technology. The front-end chip was designed in 0.35-mu m complementary metal oxide semiconductor (CMOS) technology, with consideration of a hybrid configuration. Each pixel circuit consists of a charge-sensitive amplifier (CSA) and bandpass filter, optimized for the SiC sensor. The low noise performance achieved an equivalent noise charge (ENC) of 55 +/- 5e(-) (rms). The spectrum of 241Am shows an energy resolution of 1.72 keV (FWHM) at 17.8-keV gamma-rays at room temperature. The obtained image with Sr-90 is a proof of a single minimum ionizing particle (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 coherent muon-to-electron transition (COMET) muon experiment at the Japan proton accelerator research complex (J-PARC).