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. 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 little data exist on these processes in detail, as most studies aim at higher irradiation fluences, where these processes have already taken course.
We present results from an irradiation study focusing on lower irradiation fluences between $10^{10}-10^{14}$ $\text{p}^{+}/\text{cm}^2$, using an in-situ measurement method which allows for the characterization of the same sample at different fluences throughout the irradiation. Three different SiC PiN detector samples have been irradiated and measured at the MedAustron ion therapy center. The detector samples all have an active area of $3\times 3\: \text{mm}^2$ and were picked from two different wafers with different active thicknesses and doping concentrations. Proton beams with an energy of $252\:\text{MeV}$ were used with clinical beam intensities of $\sim 10^{10} \:\text{p}^{+}\text{/spill}$ and a spill length of 1$\:$s.
Current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured several times during the irradiation, as well as charge collection efficiency (CCE) before and after the irradiation.
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 within the same samples.
These results provide a unique perspective on the gradual manifestation of radiation damage induced effects in SiC detectors and present an opportunity to develop and further enhance radiation damage models.
Additionally, this study gives an insight to the expected lifetime of SiC detectors in medical applications.
| Type of presentation (in-person/online) | in-person presentation |
|---|---|
| Type of presentation (I. scientific results or II. project proposal) | I. Presentation on scientific results |