UHV-STM system combined with MBE

To study the initial growth stage of molecular beam epitaxy (MBE), we develop a scanning tunneling microscope (STM) combined with MBE. The designs of the STM unit, current detection circuit, and control software are described. The STM unit operates in UHV environment and is designed to mount the same sample holder used during the MBE growth. The rigid sample transfer mechanism is constructed allowing the certain amount of clearance required to an UHV transfer system. The bias voltage is applied to the tip instead of the sample, because the MBE grown sample is electrically grounded to its sample holder. The control software is developed for scan control, data acquisition and imaging. An ordered modular structure of the software and an easy maintenance is achieved by means of the object-oriented programming method