Integrated cryogenic scanning tunneling microscopy and sample preparation system

A scanning tunneling microscope (STM) operable from room temperature to 1.5 K with an integrated sample preparation chamber has been constructed and successfully tested. Both the sample and the tunneling tip can be cleaned and/or modified in a UHV processing chamber which is connected at the top of a liquid-helium flow cryostat. The STM is mounted to a threaded rod inside the cryostat so that it can be translated vertically. This allows a newly prepared sample/tip to be transferred onto the STM and lowered into a cryogenic environment without breaking vacuum, minimizing surface contamination which causes significant tunneling problems at cryogenic temperatures.