Al2O3 e-beam evaporated onto silicon (100)/SiO2 by ToF-SIMS

The authors report the positive and negative ion time-of-flight secondary ion mass spectrometry characterization of a thin film of e-beam evaporated alumina on a silicon substrate using Bi3 ++ primary ions at 50 keV, where this film prevents poisoning of a Fe catalyst in carbon nanotube growth. The positive ion spectrum showed a strong Al+ signal, while the negative ion spectrum showed strong peaks due to AlO−, AlO2 −, AlO3H2 −, and OH−.