Scanning probe microscopy (SPM) dimensional metrology efforts at the U.S. National Institute of Standards and Technology are reviewed. The main SPM instruments for realizing the International System of Units (SI) are the Molecular Measuring Machine, the Calibrated Atomic Force Microscope, and the Critical Dimension Atomic Force Microscope. These are optimized for long-distance measurements, three-dimensional measurements over conventional SPM distances, and critical dimension or line width measurements respectively. 10 mm distances have been measured with relative standard uncertainty, u, of 1.5 x 105; step heights at the 100 nm scale have been measured with relative u of 5 x 103; and sub-micrometer line widths have been measured with u = 0.8 nm.
Citation: Measurement Science & Technology
Pub Type: Journals
SPM, AFM, traceable dimensional metrology, nanometrology, uncertainty budget