Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker
Journal
Journal of Instrumentation
Journal Volume
16
Journal Issue
11
Date Issued
2021
Author(s)
Adam W. et al. (The Tracker Group of the CMS Collaboration)
Abstract
During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. The last step in evaluating the optimal design for the mass production of about 200 m2 of silicon sensors was to compare sensors of baseline thickness (about 300 μm) to thinned sensors (about 240 μm), which promised several benefits at high radiation levels because of the higher electric fields at the same bias voltage. This study provides a direct comparison of these two thicknesses in terms of sensor characteristics as well as charge collection and hit efficiency for fluences up to 1.5 × 1015 neq/cm2. The measurement results demonstrate that sensors with about 300 μm thickness will ensure excellent tracking performance even at the highest considered fluence levels expected for the Phase-2 Outer Tracker. ? 2021 CERN.
Subjects
Particle tracking detectors (Solid-state detectors); Radiation damage to detector materials (solid state); Radiation-hard detectors; Si microstrip and pad detectors; Doping (additives); Electric fields; Phosphorus; Silicon detectors; Substrates; Detector materials; Micro-strips; Particle tracking; Particle tracking detector (solid-state detector); Phase 2; Radiation damage to detector material (solid state); Radiation hard detectors; Si microstrip and pad detector; Solid state detectors; Tracking detectors; Radiation damage
Type
journal article