抄録
Polycrystalline chromium metal plates (purity>99.99%) were implanted with nitrogen ions (N2+) at energies of 500keV, 1MeV, 1.5MeV and 2MeV and the doses of from 3×1017 to 1×1018N atoms/cm2. Multiple implantation at beam energies of 2MeV-1.5MeV-1MeV was undertaken in an attempt to form a thick nitride layer. Substrate temperature was varied from ca, 40°C to 400°C to investigate the temperature dependence of the crystallinity of the modified layer. The depth profile of nitrogen concentration was investigated by Rutherford backscattering spectrometry (RBS) and the crystallinity of the nitride layer was studied by XRD. An amorphous nitride layer was formed when substrate temperature was kept down to 40°C-80°C. When substrate temperature was higher than 170°C, the nitride layer formed had relatively good crystallinity. At 400°C, a homogeneous layer of Cr2N was formed.
