Speaker
Description
4H-silicon carbide (4H-SiC) is an emerging wide bandgap detector material in high-energy physics due to its superior temperature stability and low dark current compared to silicon detectors. The wide bandgap of 4H-SiC makes it suitable for high-temperature applications and allows operation at room temperature even after irradiation.
These features, combined with SiC being insensitive to visible light, make it an ideal candidate for applications in medical physics, such as beam monitoring or dosimetry.
Critical to the performance of SiC detectors and electronics is their response to radiation damage induced defects. There exists a significant amount of literature showing the compensation of lightly doped intrinsic layers and the loss of forward conduction after neutron irradiation to fluences of around $5\times10^{14} \text{n}_{\text{eq}}/\text{cm}^2$. However, only few data exist on these processes in detail, as most studies aim at higher irradiation fluences, where these processes have already taken course. We therefore aim at a radiation study involving lower irradiation fluences and an in-situ measurement method, allowing for the characterization of the same sample at different fluences throughout the irradiation.
We present an irradiation study of a $3\times 3 \:\text{mm}^2$ SiC PiN detector performed at an ion therapy center. Proton beams with an energy of $252\:\text{MeV}$ were used with clinical beam intensities, for a total irradiation fluence in the range of $10^{14}\:\text{p}^{+}/\text{cm}^2$.
Current-voltage and capacitance-voltage characteristics were measured several times during the irradiation, along with the charge collection efficiency (CCE) before and after the irradiation. These results provide a unique perspective on the gradual manifestation of radiation damage induced effects in SiC detectors. Compared to more traditional irradiation campaigns, where multiple samples are irradiated to different fluences, these measurements allowed for a characterization of different radiation damage levels with the same sample.
Additionally, this study gives an insight to the expected lifetime of SiC detector in medical applications.
| Workshop topics | Sensor materials, device processing & technologies |
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