DEVELOPMENT OF AN ULTRAHIGH-VACUUM ATOMIC-FORCE MICROSCOPE FOR INVESTIGATIONS OF SEMICONDUCTOR SURFACES

A new atomic force microscope (AFM) adapted for ultrahigh vacuum operation is described. This AFM utilizes the optical beam deflection method to detect the cantilever displacement. Both the laser diode and the photodiode sensor are contained within the vacuum chamber. An inchworm motor mechanism is used for the tip-sample approach. Up to eight cantilevers are stored in the chamber and can be used without breaking vacuum. The vacuum system is equipped with a sample heater, an evaporation cell, a gas inlet valve, and a low-energy electron diffraction system, for observing semiconductor surfaces. Imaging of a graphite surface and a clean Si(111) surface with step structures have been obtained.