A High-Sensitivity Low-Power CMOS Sensor for a Future Neutron Personal Dosimeter

Despite a continuously increasing demand, neutron electronic personal dosimeters (EPDs) are still far from being completely established. A high sensitivity, low power consumption CMOS sensor for a future neutron personal dosimeter has been implemented in a 0.35 $\mu$ m CMOS technology. The 2.56 $,\times,$ 2.56 mm $^{2}$ sensing part is a micro-diode system of very low capacitance, implemented on the same substrate than the readout electronics. The excess electrons generated by an impinging particle are collected by the micro-diodes through thermal diffusion. The charge collection time and efficiency are the crucial points of a CMOS detector. We performed 3-D device simulations, using the commercially available Synopsys-SENTAURUS package, to address the detailed charge collection process. A charge sensitive amplifier (CSA) and a shaper are employed in the front-end readout. In this paper, the first electrical tests and $\alpha$ -measurements are presented.