Metal imaging on surface of micro- and nanoelectronic devices by laser ablation inductively coupled plasma mass spectrometry and possibility to measure at nanometer range

An analytical mass spectrometric method for the elemental analysis of nano-bioelectronic devices involved in bioengineering research was developed and applied for measurements of selected metals (Au, Ti, Pt, Cr, etc.) on interdigitated electrode array chips (IDA-chip). An imaging laser ablation inductively coupled plasma mass spectrometric (LA-ICP-MS) procedure was used to map the elements of interest on the surface of the analyzed sample. The obtained images of metals were in a good agreement and corresponded to the micro- and nanofabricated metal electrode pattern. For the analysis at nanometer resolution scale a NF-LA-ICP-MS (NF-near-field) procedure was applied, which utilize thin Ag needle to enhance laser beam energy and improve spatial resolution of the method. The results show a approximately 100x enhancement of analyte signal, when the needle was positioned in the "near-field region" to the sample surface and the laser shot was performed. In addition, mass spectrometric studies of reproducibly for five separated NF-LA shots in different places of analyzed sample yielded an RSD of the measurement of 16%.