A comparison of sputtered Ni/Cr interface depth resolution as obtained by the quartz crystal microbalance mass-loss method and Auger spectroscopy

Abstract

Sputter depth profiles of interfaces have been obtained by monitoring the change in sputtering rate as a function of sputtered depth. One very sensitive technique which we use to measure sputtering rates is the quartz crystal microbalance mass-loss method; it has been used to characterize Ni/Cr interfaces sputtered with a mass-analyzed 6 to 12 keV argon ion beam. Interface widths or interface depth resolution (90 to 10% points) obtained from the mass-loss depth profile data are compared to Auger sputter depth profile widths (1 to 4.5 keV argon ions) obtained on similar Ni/Cr thin-film materials. The somewhat narrower widths found with the mass-loss method indicate that this type of depth profiling can be used to characterize interface structures and to estimate the abruptness of an original, unsputtered interface.