Compact, combined scanning tunneling/force microscope

Abstract

We have built a combined scanning tunneling and scanning force microscope. Owing to the compact design of the instrument with Nomarski type of interferometry for lever deflection sensing, we achieved excellent stability with a total rms noise of 0.03-0.04 Å in a frequency bandwidth of 0.01 Hz-2 kHz and a spectral noise density of 2.0×10-4 Å/ √Hz at higher frequencies (>2 kHz) using cantilevers with compliances of ∼150 N m-1. Simultaneous measurement of constant current contours, the acting forces, and the system compliance allows separation of sample topography from electronic and elastic effects.