Accurate modelling of 3D-trench silicon sensor with enhanced timing performance and comparison with test beam measurements

Abstract

This paper presents the detailed simulation of a double-pixel structure for charged particle detection based on the 3D-trench silicon sensor developed for the TIMESPOT project and a comparison of the simulation results with measurements performed at the π-M1 beam at PSI laboratory. The simulation is based on the combined use of several software tools (TCAD, GEANT4, TCoDe and TFBoost) which allow to fully design and simulate the device physics response in very short computational time, O(1–100 s) per simulated signal, by exploiting parallel computation using single or multi-thread processors. This allowed to produce large samples of simulated signals, perform detailed studies of the sensor characteristics and make precise comparisons with experimental results.

Modeling of Solid State Detectors Using Advanced Multi-Threading: The TCoDe and TFBoost Simulation Packages

“…The advantage of this method is that the final electronics response describes also the electrical couplings (sensor capacitance, sensor-electronics connection impedance) that are nearly impossible to be measured. This procedure has been recently applied on the interpretation of the test beam data of the TimeSPOT 3D silicon sensors [10], performed in October 2019, leading to a very good agreement between simulation and measured data.…”

“…Known custom packages for electronics simulation, such as Allpix 2 [20], use analytical white noise models, thus without any temporal correlation between noise samples. A more realistic model can be obtained by studying the power spectral density of common front-end electronics noise, as done in [10]. The noise spectrum is generally not flat throughout the frequency domain, but it exhibits higher intensity at lower frequencies.…”

“…As an example of a real TFBoost usage with all the other steps included (signal loading, transformations, noise adding, signal analysis, plotting, etc. ), performed for the simulation and data analysis of the 2019 TimeSPOT test beam [10], the application takes approximately a few minutes to perform the full simulation of 50,000 waveforms. The same procedure, without the optimized methods described in this section, would take approximately O(10 hours), making the detailed study of the simulation practically impossible, as to optimize the different parameters of the simulation steps it is necessary to run it several times.…”

“…They have been developed within the TimeSPOT [7] collaboration but do not depend on its specific sensor technologies. TCoDe and TFBoost were recently used (and tested) to understand sensor behavior by comparing simulations with high statistic test-beam measurement collected during the first TimeSPOT sensor test-beam in 2019 [8][9][10], as well as for comparison of various 3Dsensor geometries for fast timing measurements [11].…”

4-Dimensional Trackers

“…This property can be exploited in minimising unevenness in the electric field and increasing the uniformity in signal response to obtain very high time resolutions. In the last years, results have been obtained by the TimeSPOT collaboration [56,57], which show that by proper design of the sensor layout and electrode geometry, the time resolution can be pushed well below 20 ps at room temperature. The measured resolution is limited by the front-end electronics performance, while the sensor intrinsic resolution is estimated around 10 ps.…”