Ultrahigh vacuum scanning force microscope with fiber-optic deflection sensor

We built a scanning force microscope working in ultrahigh vacuum. The lever deflection is measured by a fiber-optic interferometer. To detect large lever deflections the distance between the fiber end and the cantilever backside is controllable by a piezoelectric device. With this technique force–distance curves can be acquired even over large distances. We implemented a stepper motor with gear reduction system for coarse approach in our microscope. First measurements of thin gold films grown on mica obtained in situ at 10−8 Pa are presented.