Nanotopographical imaging using a heated atomic force microscope cantilever probe

This paper reports quantitative topographical measurements using a heated atomic force microscope (AFM) cantilever probe. The study compares topographies measured by the cantilever thermal signal to topographies measured by the laser-deflection signal of an AFM system. The experiment used 20 and 100 nm tall Si gratings as topographical test samples. The cantilever heater temperature ranged from 130 to 640 °C, and the cantilever power ranged from 1.5 to 6.6 mW. The measured topography sensitivity, which is the fractional change of the heated cantilever resistance, has a |ΔRcant|/Rcant of 4.5 × 10−5 to 1.1 × 10−3 per vertical nanometer, which is 10–100 times greater than that of similarly sized piezoresistive cantilevers. In a proof of concept demonstration, the heated cantilever measures the topography of a microfabricated platinum line of thickness 100 nm on a silicon dioxide substrate.