Bending Harmonic Atomic Force Microscopy for High Sensitivity Mapping of Microgroove Topography

This paper presents a bending harmonic atomic force microscopy (HAFM) for high sensitivity mapping of microgroove topography. Compared to traditional atomic force microscopy (TAFM), the image characteristics measured by HAFM are more accurate, and the image clarity and resolution are higher. Our harmonic probe considers the effect of tip-sample couplings on probe vibration and can prevent problems of image resolution reduction and vibration stability degradation caused by harmonic attenuation. We tested the Young's modulus of the sample and calculated the tip-sample contact's equivalent contact stiffness firstly. Then, the harmonic probe and the traditional probe were applied to scan a microgroove sample using force modulation mode. Experimental results show that the error between the width of ridge portions and the height difference between ridge and valley portions measured by HAFM and SEM is all less than 2 %, that is much lower than the error of TAFM measurements. HAFM also has high imaging accuracy at high scanning speed (0.4 seconds per line). HAFM is sensitive to changes in sample height, allowing high contrast imaging at high speeds. In summary, HAFM greatly improves the detection capability of the probe and has a good development prospect in micro- and nano operation and high precision scanning.