Modeling radiation damage in TCAD

Abstract

The aim of this work is to develop a TCAD radiation damage model at a device level, enabling a predictive insight on the electrical behaviour of detectors and aiming at their ultimate performance optimization for the operation at HL-LHC expected fluences (e.g. greater than 2.0 $\times$ 10$^{16}$ 1 MeV equivalent neutrons/cm$^2$). Our approach aims at keeping the number of fitting parameters as low as possible, at the same time accounting for new experimental evidences of relevant effects at these very high fluences (e.g. charge multiplication and avalanche effects). A physically grounded approach is being pursued, aiming at devising a not over-specific modelling while keeping predictive capabilities on the device behavior fabricated by different vendors (e.g. with different technology flavors) and in different operating conditions, e.g. at different fluences, temperatures and biasing voltages. The model development follows a test campaign with a twofold goal: from one hand, the relevant technology parameters such as oxide charge and interface trap states as a function of the irradiation dose have been measured. On the other hand, DC and AC measurements on gate-controlled diodes and MOS capacitors can be used as reference for TCAD simulation models validation purpose. The complete bulk and surface radiation damage model can be exploited for the analysis of the active behavior of different classes of new generation detectors to be used in the future HEP experiments.