Optimization of Strip Isolation for Silicon Sensors
Veröffentlicht am 22.04.2012 in Physics Procedia
Precision machines like electron-positron-colliders and b-factories demand for low material budget and high position resolution when it comes to particle tracking. A low material budget can be achieved by using thin double-sided silicon detectors (DSSDs) and lightweight construction. Since thin sensors only give low signals, one has to be very careful to achieve high charge collection effciency, which requires an appropriate sensor design. In this paper we present a detailed investigation of different p-stop patterns used for strip isolation on the n-side of double-sided microstrip sensors with n-type bulk. We developed test sensors featuring the common p-stop, the atoll p-stop and a combined p-stop pattern, and for every pattern four different geometric layouts were considered. These sensors were tested at the Super Proton Synchrotron (SPS) at CERN (Geneva, Switzerland) in a 120 GeV hadron beam. Then they were irradiated to 700 kGy with a 60Co source and subsequently tested in the same beam as before. One geometric layout of the atoll p-stop pattern turned out to perform best, both before and after irradiation. The conclusions of these tests will be applied to the design of DSSDs for the Belle II experiment at KEK (Tsukuba, Japan).
Autoren: Thomas Bergauer, Marko Dragicevic, Markus Friedl, Christian Irmler, Manfred Valentan, Erik Huemer, Wolfgang Treberspurg
Kategorie: Reviewed Paper