Design and Construction of a UHV-LT-STM System for Atom Manipulation on MBE Grown Semiconductor Surfaces

An ultra-high-vacuum low-temperature scanning-tunneling-microscope (UHV-LT-STM) capable of single atom/molecule manipulation on molecular beam epitaxy (MBE) grown semiconductor surfaces has been designed and constructed. The STM scanner design is based on a modified Besoke-Beetle type and the thermal drift of the system is less than 0.1 nm/hr, which allows to perform I-V, dI/dV and vibrational tunneling spectroscopy measurements at single atom level. The sample holding stage is designed to have electrical contact at the surface layer of the sample. This permits tunneling into wide band-gap MBE grown semiconductor surfaces at low substrate temperatures. As a demonstration, the first low temperature STM image of GaN(0001) surface at 5 K and an atom-by-atom deposition process using vertical atom-manipulation on this are also presented.