MODIFICATION OF AMORPHOUS BRIGHT CHROMIUM DEPOSITED (ABCD) FILMS BY NITROGEN ION-IMPLANTATION

The hardness of amorphous bright chromium deposited (ABCD) layers can be increased by annealing or N ion implantation. In this study the N ion implantation parameters which influence hardness have been systematically examined. These parameters include sample pretreatment, ion beam energy and total dose. The properties of the resulting films have been characterized using Auger electron spectroscopy coupled with ion sputtering depth profiling, X-ray photoelectron spectroscopy and Knoop microhardness measurements. Auger depth profiles suggest the formation of a stoichiometric CrN subsurface layer after implantation of high N doses (> 8 x 10(17) N/cm2). With higher doses this layer broadens toward the surface and N retention values decrease rapidly. Implanting at elevated temperatures increases the retained N, causes N to migrate more deeply into the bulk, and yields high hardness values.