The damage characteristics of polyethylene terephthalate (PET) have been studied under bombardment by C-60(+), Au3+ and Au+ primary ions. The observed damage cross-sections for the three ion beams are not dramatically different. The secondary ion yields however were significantly enhanced by the polyatomic primary ions where the secondary ion yield of the [M + H](+) is on average 5 x higher for C-60(+) than Au3+ and 8 x higher for Au3+ than Au+. Damage accumulates under Au+ and Au3+ bombardment while C-60(+) bombardment shows a lack of damage accumulation throughout the depth profile of the PET thick film up to an ion dose of similar to 1 x 10(15) ions cm(-2). These properties of C-60(+) bombardment suggest that the primary ion will be a useful molecular depth profiling tool. (c) 2006 Elsevier B.V. All rights reserved.