Measurements and simulations of X-ray radiation damage effects on CNM n-type 4H-SiC MOS capacitors

Khaoula Aouadj; Alessandro Fondacci; Arianna Morozzi; Daniele Passeri; Tommaso Croci; Sebastian Alexander Onder; Daniel Radmanovac; Thomas Bergauer; Serena Mattiazzo; Francesco Moscatelli

arXiv · 2605.29375

Measurements and simulations of X-ray radiation damage effects on CNM n-type 4H-SiC MOS capacitors

Khaoula Aouadj·Alessandro Fondacci·Arianna Morozzi·Daniele Passeri·Tommaso Croci·Sebastian Alexander Onder·Daniel Radmanovac·Thomas Bergauer·Serena Mattiazzo·Francesco Moscatelli

View original source ↗Read source document ↗Export metadata ↓

Abstract

Silicon carbide is a promising material for radiation-hard detectors due to its wide bandgap, low leakage current, high critical electric field, and high saturation velocity. A key obstacle for its use in high-radiation environments is the incomplete understanding of surface damage at the 4H-SiC/SiO$_2$ interface.In this work, we present a combined experimental and TCAD simulation study of X-ray radiation-induced surface damage on n-type 4H-SiC MOS capacitors fabricated at CNM (Centro Nacional de Microelectronica, Barcelona), irradiated up to 10 Mrad. High-frequency (100 kHz) and quasi-static capacitance-voltage (C--V) measurements are used to evaluate the evolution of fixed oxide charge density and interface trap density as a function of dose.A dose-dependent TCAD surface model is developed and validated against the full set of measurements. The optimized model reproduces the measured C--V characteristics across the entire irradiation range and provides a physically grounded baseline for simulations of n-type 4H-SiC-based detectors. It can be used as a starting point for predictive modeling of irradiated detectors.

Explore related subjects

physics.ins-det

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Khaoula Aouadj, Alessandro Fondacci, Arianna Morozzi, Daniele Passeri, Tommaso Croci, Sebastian Alexander Onder, Daniel Radmanovac, Thomas Bergauer, Serena Mattiazzo, Francesco Moscatelli. 2026-05-28. Measurements and simulations of X-ray radiation damage effects on CNM n-type 4H-SiC MOS capacitors. https://arxiv.org/abs/2605.29375

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Proposing, never assigning: fair allocation of control-room shifts in experimental particle physics collaborations from ranked wishes under institutional quotas

Experimental particle physics collaborations staff their detectors around the clock with members drawn from dozens of institutions. The established practice is a credit system with self-sign-up: institutions owe a quota of credit, and people take the seats they want when booking opens. This paper describes a method in which seats are instead allocated from ranked wishes under institutional quotas, the result is issued as offers that each person accepts or declines, and an independent checker recomputes every rule before anything is published: the platform proposes, never assigns, and proves that it kept the rules. The credit and quota model is inherited from current practice. Around that core the paper adds a quota rule that keeps indivisible blocks fair to institutions whose share of a period is smaller than one block, and four rules that make fairness visible beyond the count: shares of owl, weekend and holiday blocks, seats shown in the laboratory's clock and the institution's own, reachable pools for institutions that cannot travel, and booking order by balance. On a synthetic collaboration of 48 institutions and 256 eligible members, the method allocates 70 to 72 of 72 seats per period in two rounds, with a mean rank satisfaction of 84 to 95% and no rule broken; after a year of running every institution of four members or more is within 13% of its cumulative share, and the smallest institutions, which one block overshoots by arithmetic, are brought within the same range by pooling in pairs. The method is stated completely enough to be reimplemented; a reference implementation exists and is available to collaborations under license. It applies as it stands to any scientific collaboration that staffs a facility in blocks of shifts under institutional quotas.

physics.ins-det↗

arXiv2026

Real-time Tunable Probability Distributions From Perimeter-Gated SPAD TRNGs

True random number generators (TRNGs) based on the dark noise of perimeter-gated single-photon avalanche diodes (pg-SPADs) naturally produce outputs that follow a tunable Bernoulli distribution. For applications requiring non-uniform random numbers, multiple such units can be coupled, or the inherent Poisson statistics of the accumulated dark events from a single pg-SPAD can be exploited. In this work, we present the principles for extending pg-SPAD-based TRNGs from the uniform to the non-uniform regime and investigate the impact of the perimeter-gate voltage on the underlying probability distributions. The proposed concepts were experimentally validated using a prototype 64 x 64 pg-SPAD chip, fabricated in a standard 0.35 $μ$m CMOS process. Collectively, we showed that common non-uniform distributions such as Poisson, exponential, and approximated Gaussian can be achieved and tuned in real-time using pg-SPAD TRNGs.

physics.ins-det↗

arXiv2026

TCAD + Allpi$\text{x}^2$ Simulation study of MALTA2, a Depleted Monolithic Active Pixel Sensor for future tracking

In this work, a hybrid simulation framework combining TCAD and Allpi$\text{x}^2$ is presented to investigate the sensor properties of MALTA2, a depleted monolithic active pixel sensor designed for future tracking. The study starts from 3D modeling and transient simulations in TCAD, with generic doping profiles and simple well structures. The resulting doping profiles and electric field are extracted and fed into Allpi$\text{x}^2$ for high-statistics Monte Carlo simulations in both DUT-only and full-telescope mode. Simulations reveal a strong dependence of sensor performance, specifically the detection efficiency and cluster size, on the doping concentration of the N-type blanket at the sensor surface. The doping concentration is then optimized by comparing simulations with measurement data. The active depth of the depleted region of the MALTA2 sensor is estimated in both simulations and measurements using a grazing angle method, in which the sensor is positioned at various inclinations relative to the beam, covering angles from 0 to 60 degrees. Excellent agreement on active depth is obtained with the optimal doping concentration, showing a deviation of 2\% from the measured value at a threshold of 450\,$\text{e}^-$. Consequently, the framework offers a generic toolkit for sensor studies without requiring proprietary information.

physics.ins-det↗