Research on neutron-irradiated 6H-SiC crystals by x-ray diffraction

Single crystal SiC has become more and more important semiconductor material due to its excellent physical and chemical properties. The present paper reports a study of characteristics of unirradiated and irradiated SiC. 6H-SiC single crystals were irradiated at approximately 60-80 o C to a neutron fluence of 5.74×10 18 n/cm 2 .The radiation damage and the defect recovery in the single crystals were investigated by X-ray diffraction meter. The experimental observation on diffraction peaks of different crystal faces shows that there are serious damages in the neutron-irradiated 6H-SiC crystals and amorphization appears at one of the measured planes. The restoration of radiation damage occurred during the isochronal annealing process, and the recovery feature is depended on annealing temperature. The X-ray diffraction data show that the radiation damages remained almost unchanged below the temperature of 600 o C, and the healing process got more and more obvious while the annealing temperature is beyond 600 o C. It is found that beyond 600 o C the crystal structure gradually reordered and the FWHM of face (006) peak reveals a linear recovery behavior with increasing annealing temperature. High-temperature detector can be made according to the linear recovery law in order to achieve the measurement of the high-temperature environment.