Future collider experiments demand a new generation of tracking detectors with excellent spatial and temporal resolution, along with enhanced radiation hardness. Monolithic active pixel sensors (MAPS) based on silicon CMOS technology are proven to provide fine spatial and temporal resolution while being cost-effective. In terms of radiation hardness, however, wide band-gap semiconductors such as silicon carbide (SiC) promise superior performance. In this work, we make a first step towards MAPS development based on SiC-CMOS technology. We used the Fraunhofer IISB 2 mu m SiC-CMOS process to design the first stage in the electronic read-out chain of a MAPS, a charge-sensitive amplifier (CSA). Circuit simulations show that an equivalent noise charge of 95 e to 205 e is attainable for an input capacitance in the range of 0.5 pF to 4.5 pF at room temperature. The attained bandwidth of 31 kHz was primarily limited by the large size of the MOSFETs in the used SiC-CMOS technology. We believe that a further increase in integration density could make SiC-MAPS a compelling alternative to its silicon-based counterparts.

In this paper we present simulation based radiation damage modeling of 4H silicon carbide (SiC) using the technology computer aided design (TCAD) tools for up to 1 kV forward and backward bias. After verifying the TCAD framework from Global TCAD Solutions (G TS) against Sentaurus simulations for silicon we use it to approximate measurements of neutron-irradiated 4H-SiC particle detectors, i.e., p-i-n diodes. Based on our simulations we are not only able to evaluate the accuracy of the predictions but also to provide an explanation for the almost negligible current of radiated devices under high forward bias.

Due to the increased commercial availability, wide-bandgap semiconductors and their radiation hardness have recently received increased interest from the particle physics community. 4H-Silicon Carbide (SiC), especially, is an attractive candidate for future radiation-hard detectors which do not require cooling. This paper investigates the radiation hardness of 4H-SiC p-in-n detectors irradiated up to 5× 10^15 n_eq./cm^2 using UV-TCT. The samples have been operated in reverse and forward bias, which is possible due to the heavily decreased forward current after irradiation. Previous studies have already hinted at an excessive charge collection in forward bias, even exceeding a charge collection efficiency (CCE) of 100 this work, the excessive CCE in forward bias was shown to correlate heavily with the spatial profile of injected charge. For a sufficiently focused laser, the CCE starts to increase at high forward bias and even surpasses 100 of saturating as it does for a defocused laser beam. In reverse bias, the CCE was found to be independent of the beam spot size. For samples irradiated to high fluences (≥ 1× 10^15 n_eq./cm^2) the excessive CCE in forward bias is smaller and negligible at the highest fluences. Additionally, the CCE was observed to correlate to the rate of charge injection (laser pulses per second), with a logarithmic increase of the collected charge if a threshold of injected carrier density is exceeded. The mechanism of these effects is still an ongoing topic of study, however, the observations already pose implications for the accurate experimental characterization of irradiated SiC detectors.

In high energy physics experiments, tracking and vertexing is nowadays mostly done using semiconductor detectors. Among the employed detectors are hybrid pixel sensors, passive sensors and recently also depleted monolithic active pixel sensors (DMAPS), which integrate the particle sensor with frontend electronics. The dominant material for the production of such sensors currently is silicon. However, the use of silicon carbide is currently being investigated. In this work we report on our progress on the development of silicon based DMAPS. Further, we present a novel front-end circuit for passive silicon carbide detectors.

For 4H silicon carbide (4H-SiC), the values for the electron-hole pair creation energy $\epsilon_{\text{i}}$ published in the literature vary significantly. This work presents an experimental determination of $\epsilon_{\text{i}}$ using $50$ $\mu$m 4H-SiC p-n diodes designed for particle detection in high-energy physics. The detector response was measured for $\alpha$ particles between 4.2 MeV and 5.6 MeV for 4H-SiC and a silicon reference device. Different $\alpha$ energies were obtained by using multiple nuclides and varying the effective air gap between the $\alpha$ source and the detector. The energy deposited in the detectors was determined using a Monte Carlo simulation, taking into account the device cross-sections. A linear fit of the detector response to the deposited energy yields $\epsilon_{\text{i}} = (7.83 \pm 0.02)\;\text{eV}$, which agrees well with the most recent literature. For the 4H-SiC detectors, a linewidth of 28 keV FWHM was achieved, corresponding to an energy resolution of 0.5\%.

In this literature review we investigate the permittivity, density-of-state mass, band gap, impact ionization, charge carrier recombination, incomplete ionization and mobility in 4H silicon carbide. We provide a comprehensive overview over characterization methods, models and parameters to lower the entrance barrier for newcomers and allow a critical evaluation of common material property descriptions. We further highlight areas for future research by identifying gaps in the current knowledge base. For each investigated property we found a large amount of models and parameter sets based on measurements, calculations or fittings. With literal and/or graphical comparisons we reveal qualitative good agreement but also flawed data values, misinterpretations of research results and inconsistencies among multiple investigations, even those directly referencing each other. We identify parameter variations, e.g., due to temperature, with high impact that are rarely considered in 4H-SiC analyses and common values that are based on old research of deviating materials or properties. We further show the slow accommodation of recent research results within the scientific community and reveal missing characterization data but also insufficient models in state-of-the-art technology computer aided design (TCAD) tools. Overall, our review enables scientifically based decisions on 4H-SiC material parameters and unravels the demand for further investigations to validate commonly used values, confirm hypothesis and cover additional dependencies.

One challenge on the path to delivering FLASH-compatible beams with a synchrotron is facilitating an accurate dose-control for the required ultra-high dose rates. We propose the use of pulsed RFKO extraction instead of continuous beam delivery as a way to control the dose delivered per Voxel. In a first feasibility test dose rates in pulses of up to 600 Gy/s were observed, while the granularity at which the dose was delivered is expected to be well below 0.5 Gy.

The extremely low dark current of silicon carbide (SiC) detectors, even after high-fluence irradiation, was utilized to develop a beam monitoring system for a wide range of particle rates, i.e., from the kHz to the GHz regime. The system is completely built from off-the-shelve components and is focused on compactness and simple deployment. Beam tests using a 50 um thick SiC detector reveal, that for low fluences, single particles can be detected and counted. For higher fluences, beam properties were extracted from beam cross sections using a silicon strip detector. Overall accurate results were achieved up to a particle rate of 109 particles per second.

Silicon carbide (SiC) is a wide band gap semiconductor and an attractive candidate for applications in harsh environments such as space, fusion, or future high luminosity colliders. Due to the large band gap, the leakage currents in SiC devices are extremely small, even after irradiation to very high fluences, enabling operation without cooling and at high temperatures. This study investigates the effect of neutron irradiation on 50 μm p-n 4H-SiC diodes using current-voltage, capacitance-voltage, and charge collection efficiency (CCE) measurements up to neutron fluences of 1 × 10 16 n eq /cm 2 . The leakage currents of the investigated devices remained extremely small, below 10 pA at 1.1 kV reverse bias. In the forward bias, a remarkable drop of the current was observed, which was attributed to an increased epi resistivity due to compensation of the epi layer doping by deep-level defects. The CCE was evaluated for alpha particles from a radioactive source, a 62.4 MeV proton beam at the MedAustron ion therapy center and using UV-TCT. The charge collection efficiency in reverse bias was shown to scale directly with the 1 MeV equivalent fluence Φ eq as CCE∝Φ eq -0.63±0.01 . A CCE better than 50% was able to be obtained for fluences up to 1 × 10 15 n eq /cm 2 . Because of the low currents in the forward direction, particle detection was also possible in forward bias, where the CCE was found to be increased relative to reverse bias. Furthermore, a significant dependency on the amount of injected charge was observed, with the CCE surpassing 100% in alpha and UV-TCT measurements, requiring further systematic investigation.

The unique electrical and material properties of 4H-silicon-carbide (4H-SiC) make it a promising candidate material for high rate particle detectors. In contrast to the ubiquitously used silicon (Si), 4H-SiC offers a higher carrier saturation velocity and larger breakdown voltage, enabling a high intrinsic time resolution and mitigating pile-up effects. Additionally, as radia-tion hardness requirements grow more demanding in the context of future high luminosity high energy physics experiments, wide-bandgap materials such as 4H-SiC could offer better perfor-mance due to low dark currents and higher atomic displacement thresholds. In this work, the detector performance of 50 mu m thick 4H-SiC p-in-n planar pad sensors was investigated at room temperature, using an 241Am alpha source at reverse biases of up to 1100 V. Samples subjected to neutron irradiation with fluences of up to 1 x 1016 neq/cm2 were included in the study in order to quantify the radiation hardness properties of 4H-SiC. A calibration of the absolute number of collected charges was performed using a GATE simulation. The obtained results are compared to previously performed UV transient current technique (TCT) studies. Samples exhibit a drop in charge collection efficiency (CCE) with increasing irradiation fluence, partially compensated at high reverse bias voltages far above full depletion voltage. At fluences of 5 x 1014 neq/cm2 and 1 x 1015 neq/cm2, CCEs of 64 % and 51 % are obtained, decreasing to 15 % at 5 x 1015 neq/cm2. A plateau of the collected charges is observed in accordance with the depletion of the volume the alpha particles penetrate for an unirradiated reference detector. For the neutron-irradiated samples, such a plateau only becomes apparent at higher reverse bias, roughly 600 V and 900 V for neutron fluences of 5 x 1014 neq/cm2 and 1 x 1015 neq/cm2. For the highest investigated fluence, CCE behaves almost linearly with increasing reverse bias. Compared to UV-TCT measurements, the reverse bias required to deplete a sensitive volume covering full energy deposition is lower, due to the small penetration depth of the alpha particles. At the highest reverse bias, the measured CCE values agree well with earlier UV-TCT studies, with discrepancies between 1% and 5%.

The material properties of silicon-carbide (SiC) make it a promising candidate for application as a particle detector at high beam rates. In comparison to silicon (Si), the increase in charge carrier saturation velocity and breakdown voltage allows for high intrinsic time resolution while mitigating pile-ups. A larger bandgap and higher atomic displacement threshold energy suppresses dark current and potentially improves radiation hardness, respectively. In addition to the lower susceptibility to temperature variations, it allows the operation of irradiated devices at room temperature and daylight illumination. Although already known for several decades, recent developments in industrial power electronics made SiC more accessible as a potential particle detector. Repeatability, large amplitudes and timing possibilities of signal pulses produced by the ultraviolet transient current technique (UV-TCT) allow for precise performance comparison of differing samples, while efficiently monitoring the influence of alternating external conditions. We present measurement results on the performance of neutron irradiated 4HSiC p-on-n planar diodes using such a setup. Dark current levels remain in the nA range for all fluences (5×1014neq/cm2−1×1016neq/cm2), while charge collection efficiency decreases with irradiation fluence, partially compensated when operating samples at reverse voltage conditions far above full depletion.