A method to improve the quantitative analysis of SFM images at the nanoscale

Quantitative analysis of scanned force microscope (SFM) images at the nanoscale requires removing the contributions of tip size and shape from the images. Mathematical morphology provides tools for doing this but determination of the probe tip geometry is required first. Blind reconstruction is among the most popular methods for determining tip geometry. We show that, at the nanoscale, spatially anisotropic noise generally present in SFM data results in artificially asymmetric tip geometries as determined by blind reconstruction. We present an easily implemented improvement to the publicly available computer code for blind reconstruction that alleviates this problem. Experimental evidence is presented to show that the method results in tip geometries that are consistent with expected shapes based on self-imaging using very sharp surface features.