Examination of polymer/metal interface modified by self-assembled monolayer by Kelvin probe force microscopy and secondary ion mass spectrometry

Buried interfaces between a polystyrene (PS) or polar poly(methyl methacrylate) (PMMA) thin film and the gold surface patterned with CH3- and COOH-terminated alkanethiols self-assembled monolayers (SAM) were examined via Kelvin probe force microscopy. Chemical composition of the interface was probed by secondary ion mass spectrometry. The contact potential difference maps measured on the PS and the PMMA films show inverted contrast. This observation is discussed in terms of reorientations of the COOH-SAM net dipole moments induced by interactions with PMMA.