Description
The advances in FLASH radiotherapy, which has typical dose rates over 40 Gy/s, demand the development of innovative instrumentation capable of operating under that extreme radiation conditions. Beam monitoring in such environments require detectors that can sustain high particle fluxes while maintaining stability and precision. Moreover, these detectors have to be ultra-thin in order to behave as transmissive radiation detectors. This feature is essential to minimize beam perturbation during irradiation, which will allow to monitor the beam in real time, reducing potential risks to patients in case of system malfunction, and thus improving safety.
In this context, silicon carbide (SiC) has emerged as a promising semiconductor due to its high radiation hardness, its wide band gap, and its thermal and optical stability. In this work, we present the development of the first ultra-thin SiC PIN diodes designed and manufactured at the IMB-CNM through optimized micromachining techniques on a 3µm epitaxial 4H-SIC layer grown over a 6-inch 4H-SIC wafer . These devices have shown to have better performance in demanding radiation conditions than the silicon ones in terms of radiation hardness and signal response [1]. The diodes have been thinned down to a total thickness of 60µm, representing a proof of concept of transmissive SiC diodes.
This work aims to report the first results of the SiC fabrication process for beam monitoring as well as the corresponding electrical characterization.
[1] Celeste Fleta et al 2024 Phys. Med. Biol. 69 095013