ABSTRACT
18.1 IntroductionIn this chapter, we will learn measurement of nonconducting surfaces using atomic force microscopy (AFM) instead of STM. This technique uses the repulsive and attractive forces between the tip (mounted on a soft cantilever) and the sample. The movement of the cantilever (frequency shift and damping) can be detected by the input laser and the output photodiode systems. 18.2 PrincipleIn noncontact AFM, as shown in Fig. 18.1, the cantilever is always vibrated by a self-driven circuit at its resonance frequency. The equation of the cantilever motion in noncontact AFM can be written as md z
