A time - of - flight mass spectrometric study of laser fluence 4 dependencies in SnO 2 ablation : implications for pulsed 5 laser deposited tin oxide thin films

10 We report on a time-of-flight mass spectrometric study of laser fluence dependencies in the 532 nm ablation of SnO2 targets. At all fluences investigated, SnO and Sn2O2 are the primary neutral gas-phase species. The relative yield of neutral tin-containing species increases exponentially up to a fluence of ∼1.9 × 108 W cm−2, and saturates at higher fluences. The yield of metal oxide clusters (primarily Sn2O2, Sn4O4) increases in the saturated region, while the yield of bare metal species (primarily Sn, Sn2) decreases. In contrast, the peak kinetic energy of the primary neutral ablated species is insensitive to laser fluence in this range. These results support the hypothesis that the initial Sn:O stoichiometry of amorphous SnOx films grown in vacuum using pulsed laser deposition (PLD) plays an important role in the formation of -SnO during post-deposition annealing. 11 12 13 14 15 16 17 © 2003 Published by Elsevier B.V. 18