[en] Low-resistivity materials have been proposed for the fabrication of radiation-hard solid-state particle detectors. A complete analysis of low-resistivity detector performance, including the estimate of charge collection efficiency, has been carried out by using a numerical device simulator, and compared with results expected from conventional, high-resistivity devices. By exploiting the features of the CAD environment, characterization of devices over a wide range of fluences and applied biases has been possible, avoiding the actual fabrication of prototypes, as well as lengthy and expensive testing procedures. Encouraging results have been obtained: low-resistivity devices appear to provide some definite advantages in terms of long-term performance optimization

[en] In this paper, numerical analysis techniques are applied to the study of microstrip silicon detectors exploited in the field of high-energy physics. At high luminosity required by future experiments, radiation hardness of such device becomes a critical issue. The adoption of relatively low-resistivity substrates has been suggested as a key to face such a problem: simulations have been carried out to verify this assumption. Comparisons have been made in terms of depletion voltage, as well as of charge-collection efficiency, by exploiting some of the features of a customized simulation environment. Estimated, long-term radiation hardness of low-resistivity detectors favorably compares with high-resistivity ones

[en] The numerical simulation of a silicon microstrip detector is discussed. Physical models for the bulk radiation damage have been taken into account, based on a generalized Shockley-Read-Hall expression of the recombination rate. The actual shape of depletion layer, depending on the radiation fluence, has been investigated. The build-up of a dual depletion layer, as reported in some literature works, has been described and interpreted

[en] The changes of the electrical properties induced by hadron irradiation on silicon detectors have been studied by using the device level simulator HFIELDS. The model of the radiation damage assumes the introduction of radiation-induced acceptor and donor 'deep-levels'. The electric field profile and the space charge region extension have been calculated for differently irradiated structures. The simulation has been carried out at different biases in order to study the evolution of the space charge region of irradiated detectors as a function of the applied voltages, below and above the full depletion. The time-dependent current responses and the charge collection properties of the structure illuminated by a red LED light have been calculated. The use of the red light results in a shallow (quasi-surface) generation of e-h pairs in silicon, which has been properly taken into account by the simulation. The results of the simulations have been compared to experimental measurements carried out at CERN on samples irradiated with 24 GeV/c protons. The comparison results in a satisfactory agreement, and supports the physical interpretation of experimental data

[en] In this paper, a TCAD-based analysis of unconventional-geometry microstrip radiation detectors is discussed. In particular, thick-substrate and large-pitch devices, recently suggested for the adoption in outer layers of particle tracking systems have been considered. Correlation among parasitic capacitance and geometrical features is discussed, providing intuitive interpretation for experimentally observed behaviors. Influence of the substrate thickness on depletion voltage is discussed, and dependence of detector performance on the width/pitch ratio is taken into account as well, providing a complete picture of the behavior of thick-substrate devices, in view of their future use in LHC experiments

[en] In this work, the application of numerical device simulation to the analysis of high resistivity silicon microstrip detectors is illustrated. The analysis Of DC, AC and transient responses of a single-sided, DC-coupled detector has been carried out, providing results in good agreement with experimental data. In particular, transient-mode simulation has been exploited to investigate the collection of charges generated by ionizing particles. To this purpose, an additional generation term has been incorporated into the transport equations; the motion of impact-generated carriers under the combined action of ohmic and diffusive forces is hence accounted for. Application to radiation tolerance studies is also introduced

[en] In this paper, the application of device simulation techniques to the design of silicon microstrip detectors devised for the CERN-CMS experiment is illustrated. Simulation strategies are summarized, focusing on radiation-related issues. Some practical examples are discussed, related to the optimization of detectors: low-resistivity substrates are analyzed, looking for improvement of long-term radiation hardness; overhanging metal contacts are studied, aiming at preventing occurrence of breakdown and early micro-discharges; thick-substrate detectors are investigated, in view of the exploitation of large-pitch devices in the outer layers of the tracker. Some emphasis is placed on the use of simulation as a physical interpretation aid, which supports detailed understanding of the device behavior

[en] An approach to the numerical simulation of silicon microstrip detectors is discussed, with particular emphasis on the modeling of radiation damage consequences. Within the framework of a general-purpose device simulator, extension have been made aimed at describing both the transduction mechanism exploited by such devices and at providing a physically grounded account of structural modification induced by continuing exposure to radiation. In particular, influence of deep-level traps is discussed, and some limitations of simpler models are pointed out

[en] The application of a general-purpose device-simulator to the analysis of silicon microstrip radiation detector is described. Physical models include charge-collection dynamics, as well as radiation-induced deep-level recombination centers. Realistic description of multiple-strip devices can be accounted for. To allow for validation of the analysis tool, actual detectors have been measured, before and after being irradiated with neutrons. Simulation predictions agree well with experiments. Limitations of the adopted model are discussed, with reference to simulation-based comparison with higher-order models

[en] In this work, the application of the general-purpose device simulator HFIELDS to the analysis of silicon microstrip detectors is presented. In the framework of CMS collaboration, a comprehensive device characterization has been performed by means of steady-state (DC) and small-signal (AC) numerical analyses. The study of charge collection dynamics has been carried out as well, by means of transient analysis. Simulation results exhibit a good agreement with literature data, and allow for detailed insights of device behavior. This makes it possible to investigate device-performance sensitivity to fabrication and environmental parameters and highlights potential applications of numerical analysis as a device design and optimization aid. (orig.)