Deuterium retention in tungsten films deposited by magnetron sputtering

Deuterium retention in tungsten films deposited on polycrystalline bulk tungsten substrates was investigated and compared with deuterium retention in W films deposited on silicon and in polycrystalline bulk W alone. The structure of the deposited films was investigated by x-ray diffraction and scanning electron microscopy combined with focused ion beam cutting. D retention after implantation was measured by nuclear reaction analysis and temperature programmed desorption (TPD). The W films deposited on bulk W show a typical columnar epitaxial growth. After D implantation, high densities of blisters with diameters of about a hundred μ m were formed. Interestingly, the blisters are located within the W substrate well below the interface of deposited film and substrate. TPD spectroscopy reveals two D 2 release peaks at 510 and 700 K, indicating at least two different trap energies.