Photograph of the LT-STM chamber and its major components (left) and transferable sample stage connected to the transfer cryostat (right)
Low temperature Scanning Tunneling Microscope (LT-STM)
The home-build low temperature STM system contains two chambers: the STM chamber and a preparation/analysis chamber connected by a gate vale. A modified Besocke beetle type STM is installed in the STM chamber. A He-cryostat (STM cryostat) allows to cool the STM system down to 6 K. An integrated heater can heat the sample quickly up to 300 K.
A second cryostat (transfer cryostat) is installed in a manipulator in the preparation/analysis chamber with XYZ translation and rotation degrees of freedom. The sample can be fixed either on the STM for scanning tunneling microscopic and spectroscopic measurements or on the transfer cryostat for preparation (sputtering, adsorption, growth) and analysis. The sample can be transferred between these two positions without breaking the low temperature and electronic connections. The unique experimental setup allows to perform ion sputtering, molecule adsorption, thin film deposition and surface characterization at any desired temperature between ~ 15 K and 1000 K. In addition to STM, various other surface analysis tools are attached on the preparation/analysis chamber including low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and reflectance difference spectroscopy (RDS). For the sample preparation an ion sputtering gun, gas inlet system and two organic MBE sources are also mounted on the preparation/analysis chamber.