Future silicon sensors for the CMS Tracker Upgrade

For the high-luminosity phase of LHC (Large Hadron Collider) at CERN a campaign was started in the CMS (Compact Muon Solenoid) experiment to investigate different radiation hard silicon detectors. Therefore 6 in. silicon wafers were ordered to answer various questions regarding for example the radiation tolerance and the annealing behavior of different sensor material. The testing variety includes sensor versions n-in-p and p-in-n in thicknesses from 50 mu m to 300 mu m. In terms of sensor material the difference between floating zone, magnetic Czochralski and epitaxial grown silicon is investigated. For the n-in-p sensors, the different isolation technologies, p-stop and p-spray, are tested. The design of the wafer contains test structures, diodes, mini-sensors, long and very short strip sensors, real pixel sensors and double metal routing variants. The irradiation is done with mixed fluences of protons and neutrons which represent the rates of integrated hadrons that are expected in the CMS tracker after the LHC upgrade. This paper presents an overview of results from measurements of non-irradiated test structures with different technologies and also the results after irradiation. (C) 2012 Elsevier B.V. All rights reserved.