AN INVESTIGATION OF PHASE-FORMATION BY HIGH-DOSE SILICON ION-IMPLANTATION INTO NICKEL

Structural changes and phase transitions during 10(17)-10(18) ionS/CM2 Silicon ion implantation (at 100 keV) into nickel and subsequent anne aling have been studied. Single crystal Ni samples were examined by Ru therford backscattering spectrometry and channeling (RBS-C) and reflec tion high energy electron diffraction (RHEED). Polycrystalline samples were thinned after ion implantation for TEM (transmission electron mi croscope) observations which included in situ annealing at temperature s up to 800-degrees-C. The structural changes were found to be critica lly dependent on the Si concentration which builds up with increasing implantation dose. Partial amorphization occurred at intermediate dose s higher than 1 x 10(17) ions/cm2 and a complete amorphous layer forme d at a nominal dose of 4.5 x 10(17) ions/cm2 or above. The in situ ann ealing of selected prethinned specimens revealed a variety of nickel s ilicide phases depending on annealing conditions. This behaviour is di scussed in terms of the availability of Ni supply during the annealing .