Effect of Energetic Helium ion Implantation on Hydrogen Isotope Retention in Silicon Carbide

The effects of He retention and damage introduction on the D retention in SiC were studied by changing the implantation energy of He from 0.75 keV to 4.0 keV. The D and He retentions in SiC and chemical behavior of SiC were evaluated by means of thermal desorption spectroscopy (TDS) and X-ray photoelectron spectroscopy (XPS). It was found that the D retention decreased by the He retention in the same implantation depth with D2, although that increased if the implantation depth of He is larger than that of D2. In addition, free C formation would make the higher retention of D bound to C. These facts indicate that not only the introduction of damaged structures but also the He retention would govern the hydrogen isotope retention in SiC.