INTEGRATED CRYOGENIC SCANNING-TUNNELING-MICROSCOPY AND SAMPLE PREPARATION SYSTEM

A scanning tunneling microscope (STM) operable from room temperature t o 1.5 K with an integrated sample preparation chamber has been constru cted and successfully tested. Both the sample and the tunneling tip ca n be cleaned and/or modified in a UHV processing chamber which is conn ected 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 ver tically. This allows a newly prepared sample/tip to be transferred ont o the STM and lowered into a cryogenic environment without breaking va cuum, minimizing surface contamination which causes significant tunnel ing problems at cryogenic temperatures.