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

Abstract

Large area (25 mm/sup 2/) silicon drift detectors and detector arrays (5/spl times/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/sup +/) 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/sup +/) and a uniform backside p/sup +/ implant. Only 3 to 5 electrodes are needed to bias the detector plus an anode for signal collection. With a 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 Fe/sup 55/ X-rays at RT using a uniform backside detector.