Design, simulation and testing of large area silicon drift detectors and detector array for X-ray spectroscopy

Large area (25 mm²) silicon drift detectors and detector arrays (5×5) have been designed, simulated, and fabricated for X-ray spectroscopy. On the anode side, the hexagonal drift detector was designed with self-biasing spiral cathode rings (p ⁺) of fixed resistance between rings and with a grounded guard anode to separate surface current from the anode current. Two designs have been used for the P-side: symmetric self-biasing spiral cathode rings (p⁺) and a uniform backside p⁺ implant. Only 3 to 5 electrodes are needed to bias the detector plus an anode for signal collection. With graded electrical potential, a sub-nanoampere anode current, and a very small anode capacitance, an initial FWHM of 1.3 keV, without optimization of all parameters, has been obtained for 5.9 keV Fe⁵⁵ X-ray at RT using a uniform backside detector