Simulation is an important tool for concept development and first level validation of novel implementations. It also provides a deeper understanding of sensor behaviour by computing detailed filed maps. Several TCAD tools are currently in use to simulate everything form the process, to the field and charge collection up to the actual output signal and the radiation hardness of a sensor.

Using TCAD simulations (SYNOPSYS) in conjunction with SiMS data, detailed profile distributions are established and the complete geometry of an elementary detection cell is generated. To describe carrier mobility and interactions within the simulated volume, all available simulation frameworks take advantage of the diffusion, continuity and Maxwell partial differential equations, with respect to the applied model. Calculations are coupled with a finite element approach to simulate the physical parameters within the device. Simulation algorithms considering a linearized version of the transport equation modeling the global calculation as an algebraic combination of a system of linear equations. Solutions for any given geometry can be obtained by subdividing structure to finite regions, allowing for local solutions to be approximated by a polynomial function. Once individual solutions are calculated for each cell, a global representation is generated.

In radiation damage modelling, trapping levels and doping concentration variations are introduced at pr3edefined states within the substrate. Standard models are exploded, including the Hamburg, Perugia and the tri-trap models and calculations are then re-adjusted for the modified conditions. Fluences in excess of 1e16 neq/cm2 are simulated and results are compared with measurements obtained from sensor characterization. Trapping energy levels and tunnelling constants consist model dependent parameters that may be extracted by universal fitting of experimental data.

For a detailed understanding of radiation related performance degradation, several comprehensive irradiation campaigns are undertaken where dedicated test structures are simulated, irradiated and characterized in various fluences. Such measurements allow for a precise estimation of all radiation damage model parameters, which is of importance in describing detector performance in future experiments.