Molecular depth profiling of organic overlayers was performed using a mass selected fullerene ion beam in conjunction with time-of-flight ( TOF-SIMS) mass spectrometry. The characteristics of depth profiles acquired on a 300-nm trehalose film on Si were studied as a function of the impact kinetic energy and charge state of the C-60 projectile ions. We find that the achieved depth resolution depends only weakly upon energy. (C) 2008 Elsevier B. V. All rights reserved.