During the scheduled high luminosity upgrade of LHC, the world's largestparticle physics accelerator at CERN, the position sensitive silicon detectorsinstalled in the vertex and tracking part of the CMS experiment will face moreintense radiation environment than the present system was designed for. Toupgrade the tracker to required performance level, extensive measurements andsimulations studies have already been carried out. A defect model of SynopsysSentaurus TCAD simulation package for the bulk properties of proton irradiateddevices has been producing simulations closely matching with measurements ofsilicon strip detectors. However, the model does not provide expected behaviordue to the fluence increased surface damage. The solution requires an approachthat does not affect the accurate bulk properties produced by the proton model,but only adds to it the required radiation induced properties close to thesurface. These include the observed position dependency of the strip detector'scharge collection efficiency (CCE). In this paper a procedure to find a defectmodel that reproduces the correct CCE loss, along with other surface propertiesof a strip detector up to a fluence $1.5\times10^{15}$ 1 MeV n$_{\textrm{eq}}$cm$^{-2}$, will be presented. When applied with CCE loss measurements atdifferent fluences, this method may provide means for the parametrization ofthe accumulation of oxide charge at the SiO2/Si interface as a function ofdose.
展开▼
