Silicon Carbide Radiation Detectors: Progress, Limitations and Future Directions
- PDF / 1,084,827 Bytes
- 13 Pages / 612 x 792 pts (letter) Page_size
- 11 Downloads / 200 Views
Silicon Carbide Radiation Detectors: Progress, Limitations and Future Directions Frank H. Ruddy1 1 Ruddy Consulting, 2162 Country Manor Drive, Mt. Pleasant, SC 29466, U.S.A. ABSTRACT Silicon carbide has long been a promising material for semiconductor applications in high-temperature environments. Although silicon carbide radiation detectors were demonstrated more than a half century ago, the unavailability of high-quality materials and device manufacturing techniques hindered further development until about twenty years ago. In the late twentieth century, the development of advanced SiC crystal growth and epitaxial chemical vapor deposition methods spurred rapid development of silicon carbide charged particle, X-ray and neutron detectors. The history and status of silicon carbide radiation detectors as well as the influence of materials and device packaging limitations on future detector development will be discussed. Specific silicon carbide materials development needs will be identified. INTRODUCTION Silicon Carbide (SiC) semiconductor radiation detectors offer many advantages for measurement applications in high-temperature and high-radiation environments. In addition to possessing many of the advantages of conventional silicon radiation detectors, the relatively wide band gap, 3.25 eV for 4H SiC, leads to detector leakage currents that are almost three orders of magnitude lower than silicon at room temperature. In addition, the leakage currents remain low at elevated temperatures allowing the detectors to operate reliably at temperatures up to 300 ºC and higher. Other advantages of SiC include a maximum breakdown field, which is eight times that of silicon allowing higher biases to be applied leading to higher drift velocities and more efficient charge collection. The high saturated drift velocity, which is almost twice that of silicon leads to a lower trapping probability. Furthermore, SiC detectors have been shown to perform well after very high gamma-ray, charged-particle and neutron cumulative doses. SiC radiation detectors were first demonstrated more than a half century ago in 1957 [1,2]. The unavailability of high-quality SiC materials hindered further development [2-7] until the mid 1990’s, when high-quality SiC substrates and epitaxial layers were developed enabling a resurgence of SiC detector technology [8,9]. The early epitaxial SiC detectors were demonstrated for alpha particle detection. SiC detectors were subsequently demonstrated for gamma-ray detection [10], X-ray detection [11], beta-ray detection [12], thermal-neutron detection [13] and fast-neutron detection [14]. The overall development of SiC radiation detectors has been reviewed by Nava, et al. [15]. The development of SiC X-ray detectors has been reviewed by Bertuccio, et al. [16]. Neutron detection with SiC detectors has been reviewed by Franceschini and Ruddy [17] Although SiC materials technology has advanced rapidly and significantly, many limitations remain for continued development of SiC detectors. A fundamental limitation of dete
Data Loading...
