Abstract
Implantation to a pure chromium substrate of (N2++N+) ions at an ion beam energy of 90keV and of N2+ ion at beam energies of 500keV and 1MeV were followed by investigation of the depth distribution of nitrogen by Rutherford backscattering spectrometry (RBS). The process of redistribution by heat treatment also studied.
Depth distribution results revealed that RBS is effective for analyses based on the total amount of ion implantation of gaseous elements such as nitrogen. The nitrogen distribution resulting from implantation carried out at high dose also showed a Gaussian shape. The nitrogen distribution obtained from low-energy ion implantation was coincident with the results of a simulation using the LSS theory.
Excess implanted ion did not form chromium nitrides, but remained unreacted as nitrogen gas and formed blisters.
Nitrogen heat treated at 1073K for 1h in vacuum changed to trapezoidal distribution. It was confirmed that the upper limit concentration was dependent on the Cr2N phase and redistribution occurred to maintain its phase. This redistribution was interpreted in terms of the nitriding of the whole implanted layer, as a result of a process particle growth with the Cr2N particles as nuclei.
