D²R₁: A 2-D X-Ray Detector for CdTe-Based Fine Pitch and High-Energy Resolution Imaging Spectroscopy

This paper describes a 16 × 16 pixels CdTe-based X-ray detector named dimension 2 revision 1 (D²R₁) with a pixel size of 300 μ m × 300 μ m. An application-specific integrated circuit (ASIC) is interconnected to a CdTe detector by means of an indium gold stud bonding process. This ASIC has a mean equivalent noise charge of 29 el.rms (at 0 pF). The combination of a low capacitance interconnection and low-dark-current detector (0.5 pA) with an optimized ASIC results in a spectral resolution of 584-eV full-width at half-maximum at 60 keV, an energy threshold of 2 keV with a dynamic range of 250 keV. A filtering stage made of a multicorrelated double sampling allows the system to measure X-ray photons at a frequency of 10 kcounts/s typically suited for low photon flux less than 3000 photons cm^-2 s^-1. The energy range, resolution, and timing capability of D²R₁ can suite a variety of different applications such as X-ray astrophysics, nuclear safety, or medical applications.