Imaging by time-of-flight secondary ion mass spectrometry of plasma patterned metal and oxide thin films

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging is employed to characterize the surface of patterned noble metal (Pt) and titania (TiO2) thin films deposited on oxidized silicon wafers. ToF-SIMS is used to follow the different process steps during the thin films patterning as well as the post-processing cleaning. Both positive and negative ToF-SIMS modes reveal the presence of contaminants, due to the etching processes (Cl- Al-,(+)), but only on the etched surfaces. Elements due to the post-processing cleaning (K+, Na+, Pb+) and photoresist residues are also detected but on the entire wafer surface. The utility of these chemically well-defined titania/platinum patterns is demonstrated for the,selective adsorption of phosphonic acid derivatives. Typical fragments of phosphonic acid groups, i.e. PO2- and PO3- show their preferential adsorption on TiO2. (C) 2002 Elsevier Science B.V. All rights reserved.