9-13 July 2012
RBS-Channelling Investigation of Radiation Damage and Diffusion of Krypton implanted into 6H-SiC
Presented by Mr. Chemist MABENA on 10 Jul 2012 from 15:30 to 15:50
Type: Oral Presentation
Track: Track A - Division for Condensed Matter Physics and Materials
The diffusion of krypton (Kr) implanted into 6H-SiC at three different temperatures, i.e. 23 °C (RT); 350 °C and 600 °C, was investigated using the RBS and channelling techniques. Implantation at 23 °C resulted in an amorphous SiC layer on the 6H-SiC. The higher temperature implantations retained the crystalline structure of 6H-SiC, with more distortions at 350 °C as compared to the 600 °C implantation. Sequential isochronal annealing for 5 hours in the temperature range 1000 °C – 1500 °C in steps of 100 °C was performed to assess the diffusion of the implanted Kr in 6H-SiC. For the room temperature implanted samples, diffusion of Kr did not start until 1200 °C, with significant diffusion taking place at 1300 °C. At 1400 °C, the diffusion was accompanied by the loss of Kr from the surface of the SiC. At 1500 °C, thermal etching of the SiC made diffusion measurements unreliable. Consequently, the activation energy of the Kr diffusion and pre-exponential factor were only determined in the temperature range 1100 °C – 1400 °C; and were E<sub>a</sub> = 17.2×10<sup>-18</sup> J and D<sub>0</sub> = 4.45×10<sup>-10</sup> m<sup>2</sup>s<sup>-1</sup> , respectively. No diffusion took place in both the 350 °C and the 600 °C implanted samples in the annealing temperature range.
Prof. J.B Malherbe email@example.com