We have used a CF3+primary ion source for some typical depth profiling applications In secondary ion mass spectrometry and compared Its performance with the conventionally used O2+source. At the same accelerating potential, steady-state secondary Ion emission conditions are reached much faster under CF3+than under O2+bombardment. Shallow implant profiles can be measured with better definition. This improvement is directly related to the shorter converted layer range produced at 5 keV CF3+versus 5 keV O2+. The better depth solution found under CF3+ bombardment may also be rationalized by the same reason of a shorter Intermixed range at the Interface. However, this is shown at least in part to be due to a smoother surface generated compared to the surface after O2+ bombardment. © 1988, American Chemical Society. All rights reserved.