Optimization of front-end design in imaging and spectrometry applications with room temperature semiconductor detectors

This paper addresses the optimization of front-end design in position sensing, imaging and high-resolution energy dispersive analysis with room temperature semiconductor detectors. The focus is on monolithic solutions able to meet the requirements of high functional densities set by multielectrode, finely segmented detectors. Front-end architectures featuring additional functions besides charge measurements, as demanded by the need of acquiring and processing multiparametric information associated with the detector signals will be discussed. Noise will be an issue of dominant importance in all the following analysis. The advent of CMOS processes featuring submicron gate length and gate oxide thicknesses in the few nanometers region is overturning some of the classical criteria in the choice of the front-end device. The achievement of the limits in resolution requires a strict control of the noise contribution from the current amplifier which ordinarily follows the front-end element in the charge-sensitive loop. This aspect becomes more crucial in designing front-end systems with submicron processes.