Correction of Interferometric High-Order Nonlinearity Error in Metrological Atomic Force Microscopy

Abstract Metrological atomic force microscopes (Met. AFMs) with built-in interferometers are one of the main workhorses for versatile dimensional nanometrology. The interferometric nonlinearity error, particularly high-order (i.e., 3rd- and 4th-order) errors, is a dominant error source further improving their metrology performance, which cannot be corrected using conventional Heydemann correction method. To solve this problem, two new methods were developed. One uses capacitive sensor embedded in Met. AFM, other applies an external physical artifact flat surface. Both can applied very conveniently effectively reduce error. In paper, propagation (residual) step height calibrations examined. Finally, performance improved tool verified calibration highly demanding industrial sample. For measurements performed at 25 different positions repeated six times, standard deviation total 150 measured values 0.08 nm, includes contributions from reproducibility sample inhomogeneity. This research has significantly our nanometrology service. instance, extended measurement uncertainty ( k = 2) reduced 1.0 to 0.3 nm or etching depth calibrations.