Characterisation of SiC radiation detector technologies with synchrotron X-rays

TL;DR

This study evaluates different SiC diode configurations for radiation detection using synchrotron X-rays, demonstrating their effectiveness and uniformity in low-energy X-ray environments with high intensity.

Contribution

It provides a comparative analysis of four SiC diode configurations, including novel epitaxial graphene contacts, for radiation detection performance under synchrotron X-ray irradiation.

Findings

Good linearity at 0 V bias in all configurations

Over-response of 12-19% due to metallic layer interactions

Effective detection of low-energy X-rays at high intensities

Abstract

To cope with environments with high levels of radiation, non-silicon semiconductors such as silicon carbide detectors are being proposed for instrumentation. 4H-SiC diodes for radiation detection have been fabricated in the IMB-CNM Clean Room, for which different strategies to define the electrical contact of the implants had been implemented, in an attempt to optimise the technology for, e.g., medical applications or low energy radiation detection, as the material choice can affect the sensitivity of the device. Among these technologies, it is included an epitaxially-grown graphene layer as part of the electrical contact. In this paper, a selection of four configurations of the IMB-CNM SiC diodes are characterised in terms of radiation detector response. Photodiode performance under 20 keV X-rays irradiation in the XALOC beam line at ALBA Synchrotron is presented. Over-responses in the range of 12-19% linked to the interaction of the radiation with the metallic layers are observed. A good uniformity response as well as a good linearity at 0~V bias is reported, even in the under-depleted devices. This work exemplifies the good performance of SiC detectors fabricated at IMB-CNM specifically for low-energy X ray characterization at high X-ray intensities.