DESIGN AND DETAILED ANALYSIS OF A SCANNING TUNNELING MICROSCOPE

A scanning tunnelling microscope (STM) is described which uses a double-lever reduction system with a single micrometer-drive for the coarse sample-to-tip approach and a thermally compensated single-tube piezo scanner for the tip movement. The microscope is equipped with versatile analogue electronics, and the data acquisition is computer-automated. The principal considerations are two main problems in the design of the STM electronics: the current control circuit and the current-sensing preamplifier. The performance of the STM is illustrated with images of gold and graphite samples.