Combining electrostatic field simulations with Monte Carlo methods enables realistic modeling of the detector response for novel monolithic silicon detectors with strongly non-linear electric fields. Both the precise field description and the inclusion of Landau fluctuations and production of secondary particles in the sensor are crucial ingredients for the understanding and reproduction of detector characteristics.
In this paper, a CMOS pixel sensor with small collection electrode design, implemented in a high-resistivity epitaxial layer, is simulated by integrating a detailed electric field model from finite element TCAD into a Monte Carlo based simulation with the Allpix$^2$ framework. The simulation results are compared to data recorded in test-beam measurements and very good agreement is found for various quantities such as cluster size, spatial resolution and efficiency. Furthermore, the observables are studied as a function of the intra-pixel incidence position to enable a detailed comparison with the detector behavior observed in data.
The validation of such simulations is fundamental for modeling the detector response and for predicting the performance of future prototype designs. Moreover, visualization plots extracted from the charge carrier drift model of the framework can aid in understanding the charge propagation behavior in different regions of the sensor.
Allpix$^2$ is a versatile, open-source simulation framework for silicon pixel detectors. Its goal is to ease the implementation of detailed simulations for both single sensors and more complex setups with multiple detectors. While originally created for silicon detectors in high-energy physics, it is capable of simulating a wide range of detector types for various application scenarios, through its interface to Geant4 to describe the interaction of particles with matter, and the different algorithms for charge transport and digitization. The simulation chain is arranged with the help of intuit…
Allpix$^2$ (read: Allpix Squared) is a generic, open-source software framework for the simulation of silicon pixel detectors. Its goal is to ease the implementation of detailed simulations for both single detectors and more complex setups such as beam telescopes from incident radiation to the digitised detector response. Predefined detector types can be automatically constructed from simple model files describing the detector parameters. The simulation chain is arranged with the help of intuitive configuration files and an extensible system of modules, which implement separate simulation steps…
The paper presents the simulation studies of 10 $μ$m pitch microstrips on a fully depleted monolithic active CMOS technology and describes their potential to provide a new and cost-effective solution for particle tracking and timing applications. The Fully Depleted Monolithic Active Microstrip Sensors (FD-MAMS) described in this work, which are developed within the framework of the ARCADIA project, are compliant with commercial CMOS fabrication processes. A TCAD simulation campaign was performed in the perspective of an upcoming engineering production run with the aim of designing FD-MAMS, stu…
A CMOS pixel sensor, named Supix-1, is developed for a pixelated silicon tracker for the Circular Electron-Positron Collider (CEPC) project. The sensor, consisted of nine sectors varying in pixel sizes, diode sizes and geometries, is fabricated with a 180 nm CMOS Image Sensor (CIS) process to study the particle detection performance of enlarged pixels. In this work, the radiation-induced effects on the charge collection of the sensor under the fluence of 1 $\times$ 10^13 1 MeV neq/cm^2 are studied by the measurements with the radioactive source of Fe-55 and the Technology Computer Aided Design…
The CLIC Tracker Detector (CLICTD) is a monolithic pixel sensor featuring pixels of 30um x 37.5um and a small collection diode. The sensor is fabricated in a 180 nm CMOS imaging process, using two different pixel flavours: the first with a continuous n-type implant for full lateral depletion, and the second with a segmentation in the n-type implant for accelerated charge collection. Moreover, CLICTD features an innovative sub-pixel segmentation scheme that allows the digital footprint to be reduced while maintaining a small sub-pixel pitch. In this contribution, test-beam measurements for the …
An ever-increasing demand for high-performance silicon sensors requires complex sensor designs that are challenging to simulate and model. The combination of electrostatic finite element simulations with a transient Monte Carlo approach provides simultaneous access to precise sensor modelling and high statistics. The high simulation statistics enable the inclusion of Landau fluctuations and production of secondary particles, which offers a realistic simulation scenario. The transient simulation approach is an important tool to achieve an accurate time-resolved description of the sensor, which …
Significant progress has been made to develop silicon pixel technologies for use in the vertex and tracker regions of the proposed Compact Linear Collider (CLIC) detector design. The electron-positron collisions generated by this linear accelerator provide a clean, low-radiation environment for the inner detectors. However, physics-driven performance targets, the CLIC beam structure, and occupancies from beam-induced backgrounds place challenging requirements on detector technologies for this region. A pixel pitch down to 25 x 25$μ$m$^{-2}$, material budget $\leq$ 0.2-2$\%X_0$ per layer, avera…
Modern silicon tracking detectors based on hybrid or fully integrated CMOS technology are continuing to push to thinner sensors. The ionization energy loss fluctuation in very thin silicon sensors significantly deviates from the Landau distribution. Therefore, we have developed a charge deposition setup that implements the Bichsel straggling function, which accounts for shell-effects. This enhanced simulation is important for comparing with testbeam or collision data with thin sensors as demonstrated by reproducing more realistically the degraded position resolution compared with naïve ionizat…
A single-photon CMOS image sensor design based on pinned photodiode (PPD) with multiple charge transfers and sampling is described. In the proposed pixel architecture, the photogenerated signal is sampled non-destructively multiple times and the results are averaged. Each signal measurement is statistically independent and by averaging the electronic readout noise is reduced to a level where single photons can be distinguished reliably. A pixel design using this method has been simulated in TCAD and several layouts have been generated for a 180 nm CMOS image sensor process. Using simulations, …
The physics aims at the proposed future CLIC high-energy linear $e^+ e^-$ collider pose challenging demands on the performance of the detector system. In particular the vertex and tracking detectors have to combine precision measurements with robustness against the expected high rates of beam-induced backgrounds. A spatial resolution of a few microns and a material budget down to 0.2\% of a radiation length per vertex-detector layer have to be achieved together with a few nanoseconds time stamping accuracy. These requirements are addressed with innovative technologies in an ambitious detector …
Application of exhaustive simulation flow for advanced performance prediction of monolithic active pixel sensors
Marietta Blau Institute for Particle Physics, Austrian Academy of Sciences（马里埃塔·布劳粒子物理研究所，奥地利科学院）；University of Bergamo（贝加莫大学）；University of Pavia（帕维亚大学）；Aix Marseille Univ, CNRS/IN2P3, CPPM（艾克斯-马赛大学，法国国家科学研究中心/欧洲核子研究组织粒子物理合作组，普罗旺斯粒子与天体物理中心）；University of Applied Sciences and Arts Dortmund（多特蒙德应用科学与艺术大学）；High Energy Accelerator Research Organization (KEK)（高能加速器研究机构（KEK））；The Graduate University for Advanced Studies (SOKENDAI)（综合研究大学院大学（SOKENDAI））；Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo（汤川理论物理学研究所-WPI，东京大学）；Department of Physics, University of Tokyo（东京大学物理系）；Instituto de Fisica Corpuscular (IFIC), CSIC-UV（粒子物理研究所（IFIC），西班牙高等科学研究委员会-瓦伦西亚大学）；Queen Mary University of London（伦敦大学玛丽女王学院）；College of Physics, Jilin University（吉林大学物理学院）
- Paper withdrawn by the author - CMOS Monolithic Active Pixel Sensors for charged particle tracking are considered as technology for numerous experiments in heavy ion and particle physics. To match the requirements for those applications in terms of tolerance to non-ionizing radiation, it is being tried to deplete the sensitive volume of the, traditionally non-depleted, silicon sensors. We study the feasibility of this approach for the common case that the collection diodes of the pixel are small as compared to the pixel pitch. An analytic equation predicting the thickness of the depletion de…
CLIC is a proposed linear $e^{+}e^{-}$ collider with center-of-mass energies of up to $3\,\textrm{TeV}$. Its main objectives are precise top quark and Higgs boson measurements, as well as searches for Beyond Standard Model physics. To meet the physics goals, the vertex and tracking detectors require not only a spatial resolution of a few micrometers and a very low material budget, but also timing capabilities with a precision of a few nanoseconds to allow suppression of beam-induced backgrounds. Different technologies using hybrid silicon detectors are explored for the vertex detectors, such a…
The Tangerine project aims to develop new state-of-the-art high-precision silicon detectors. Part of the project has the goal of developing a monolithic active pixel sensor using a novel 65 nm CMOS imaging process, with a small collection electrode. This is the first application of this process in particle physics, and it is of great interest as it allows for an increased logic density and reduced power consumption and material budget compared to other processes. The process is envisioned to be used in for example the next ALICE inner tracker upgrade, and in experiments at the electron-ion col…
CLIC is a proposed linear e+e- collider designed to provide particle collisions at center-of-mass energies of up to 3 TeV. Precise measurements of the properties of the top quark and the Higgs boson, as well as searches for Beyond the Standard Model physics require a highly performant CLIC detector. In particular the vertex detector must provide a single point resolution of only a few micrometers while not exceeding the envisaged material budget of around 0.2% X0 per layer. Beam-beam interactions and beamstrahlung processes impose an additional requirement on the timestamping capabilities of t…
Charge collection parameterization of MALTA2, a depleted monolithic active pixel sensor
Humboldt University of Berlin（柏林洪堡大学）；Indian Institute of Technology Madras（马德拉斯印度理工学院）；University of Oxford（牛津大学）；University of Glasgow（格拉斯哥大学）；Stony Brook University（石溪大学）；CERN（欧洲核子研究中心）；Ankara University（安卡拉大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；University of Birmingham（伯明翰大学）
本文提出了一种快速模拟方法，用于 depleted monolithic active pixel sensor，通过数据驱动的电荷收集和传播参数化，为无法获取工艺细节的传感器提供高效替代方案，实现了高精度的像素效率模拟。
In order to achieve the challenging requirements on the CLIC vertex detector, a range of technology options have been considered in recent years. One prominent idea is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel readout chips. Recent results have shown the approach to be feasible, though more detailed studies of the performance of such devices, including simulation, are required. The CLICdp collaboration has developed a number of ASICs as part of its vertex detector R&D programme, and here we present results on the perfo…
