Effects of helium on titanium films and the helium diffusion

Using direct current-magnetron sputtering,Helium-trapped Ti films with a He/Ar mixture was studied.The relative helium content,helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry(EPBS)and X-ray diffraction(XRD).It was found that helium diffusion enhanced as more helium trapping into Ti films,and the He holding ratios were 95.9%,94.9%,93.9%,82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.%,19.5 at.%,19.7 at.%,48.3 at.% were measured again 4 months later,respectively.The diffraction peaks be-came weak and wider,the peak of(002)plane was shifted to smaller diffraction angles and the relevant interplanar spacing d(hkl)increased gradually as more helium trapping into Ti films.The main peak was made trending to the(101)plane by both higher deposition temperature and more helium trapping.