High temperature scanning tunneling microscopy during molecular beam epitaxy

Abstract

We have built and tested a system that is capable of simultaneous molecular beam deposition and scanning tunneling microscopy (STM) imaging at T=300–1000 K. The STM is based on the beetle-type design. Active compensation of thermal drift reduces the residual drift in the images to ∼2 Å/min at 850 K sample temperature. Measurements at varying sample temperatures are also feasible. Due to the open design of the STM, a molecular beam from a commercial microevaporator is aimed between tip and sample. With our system, simultaneous molecular beam epitaxy (MBE) and STM experiments during growth at high temperature are feasible. This method (MBSTM) provides the possibility to follow the MBE growth process with the STM in a real in situ way. The operation characteristics and performance of this instrument will be shown using examples of silicon homoepitaxy and Ge/Si heteroepitaxy.