Characterization of Si hybrid CMOS detectors for use in the soft X-ray band

摘要

We report on the characterization of four Teledyne Imaging Systems HAWAII Hybrid Si CMOS detectors designed for X-ray detection. Three HI RG detectors were studied along with a specially configured H2RC. Read noise measurements were performed, with the lowest result being 7.1 e~- RMS. Interpixel capacitive crosstalk (IPC) was measured for the three HIRGs and for the H2RG. The HIRGs had IPC upper limits of 4.0-5.5% (up & down pixels) and 8.7-9.7% (left & right pixels), indicating a clear asymmetry. Energy resolution is reported for two X-ray lines, 1.5 & 5.9 keV, at multiple temperatures between 150 and 210 K. The best resolution measured at 5.9 keV was 250 eV (4.2%) at 150 K, with IPC contributing significantly to this measured energy distribution. The H2RG, with a unique configuration designed to decrease the capacitive coupling between ROIC pixels, had an IPC of 1.8 ± 1.0% indicating a dramatic improvement in IPC with no measurable asymmetry. We also measured dark current as a function of temperature for each detector. For the detector with the lowest dark current, at 150 K, we measured a dark current of 0.020 ± 0.001 (e~- s~(-1) pixel~(-1)). There is also a consistent break in the fit to the dark current data for each detector. Above 180 K, all the data can be fit by the product of a power law in temperature and an exponential. Below 180 K the dark current decreases more slowly; a shallow power law or constant must be added to each fit, indicating a different form of dark current is dominant in this temperature regime. Dark current figures of merit at 293 K are estimated from the fit for each detector.