A novel low profile atomic force microscope compatible with optical microscopes

Abstract

A novel low profile atomic force microscope (AFM) compatible with conventional optical microscopes has been developed. This AFM can be fitted with two types of scanners for varying applications. For small area scanning, three stacked lead zirconite titanate (PZT) actuators are employed: a short-stacked PZT which moves the AFM cantilever vertically and two long-stacked PZTs which move the cantilever horizontally. For wide area scanning, flexures are used to enlarge the scan area horizontally. To measure cantilever deflection by the optical level method, mirrors are attached to the actuators enabling the laser beam to track the cantilever's movement. Each scanner has a total height of 13 mm, and can comfortably fit between a sample and a 50× objective lens in an upright optical microscope, or fit between a sample and a condenser lens in an inverted optical microscope. The range of the small area scanner is 16×16×4 μm while that of the wide area scanner is 100×100×4 μm. This low profile AFM achieved a noise performance of 0.6 Å rms. According to experimental results and finite element method simulations, the performances of the low profile scanners were comparable with that of conventional tube scanners.