Lateral Resolution of Imaging Surface-Analytical Instruments as SIMS, AES and XPS: Application of the BAM-L200 Certified Reference Material and Related ISO Standards

The certified reference material BAM-L200 is a nanoscale stripe pattern for length calibration and specification of lateral resolution with stripe widths ranging down to 1 nm. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1-xAs and InxGa1-xAs on a GaAs substrate. Calibration distances, grating periods and stripe widths have been certified by Transmission Electron Microscopy (TEM) with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers a plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface analytical instruments. BAM-L200 will fully support the implementation of the revised International Standard ISO 18516 which is based on knowledge outlined in the Technical Report ISO⁄TR 19319:2013. Additionally, the determination of the Field of View (FoV) in the small area modes of X-ray Photoelectron Spectroscopy (XPS) is addressed, too. A test sample is introduced for a measurement of the intensity contribution from outside the nominal Field of View (FoV).