Analysis of interstrip capacitance of Si microstrip detector using simulation approach

Abstract

The harsh radiation environment in future high energy physics experiments like large hadron collider provides a challenging task to the performance of Si microstrip detectors. The performance of Si microstrip detectors is scaled in terms of the breakdown performance of the device while having no adverse effect on signal/noise ratio (S/N). The adoption of overhanging metal electrode is known to limit the breakdown risks in high voltage biased microstrip detectors. The present study aims at investigating the effect of width of overhanging metal electrode on the interstrip capacitance, and hence on noise performance of silicon microstrip detectors to be used in the Preshower detector of the electromagnetic calorimeter at compact muon solenoid. The influence of various geometrical and physical parameters like strip-width/pitch ratio of the strips, surface state fixed oxide charge and relative permittivity of the passivant on the interstrip capacitance of Si detectors is also discussed. The adoption of limited overhanging metal electrode is shown to have positive impact on interstrip capacitance while improving the breakdown performance of the device also.