Paper EW-TuA7
Chemical Sample Characterisation on the Nanoscale: Imaging XPS with Ultimate Spatial Resolution

Tuesday, October 16, 2007, 3:40 pm, Room Exhibit Hall

In this contribution we briefly summarize the current status of novel instrument design in imaging XPS (iXPS) achieving ultimate resolution beyond today’s traditional limits. In iXPS a great obstacle for higher resolution is the limited X-ray brilliance in the analysis area in combination with the small electron acceptance angle of current spectrometers. Today commercial laboratory instruments are limited to approx. 3 μm resolution. Acquisition times as well as time for experiment set up increase unacceptably when the attempt is made to utilize this kind of resolution routinely. In particular with those instruments acquiring each image pixel sequentially by either scanning the X-ray beam or the analysis spot. We present first results acquired with a NanoESCA instrument installed at LETI. A new lens concept provides a huge progress for the acceptance angle of photoelectrons. This is combined with a patented aberration compensated analyzer allowing the acquisition of typically 640x512 image pixels in a single shot. This offers the unique possibility to achieve sub micron image resolution routinely as well as small spot spectra from well-defined areas below 1μm diameter, within reasonable acquisition times.