AMBIENT PRESSURE SCANNING TUNNELING MICROSCOPE IMAGING OF HYDROGEN-PASSIVATED SI/GE MULTILAYERS

In an attempt to observe the band offset and atomic structure of the Si-Ge interface directly we have imaged cross-sections of Si/Ge multilayer structures with scanning tunneling microscopy (STM). The samples were imaged in a nitrogen ambient and consisted of cleaved cross-sections that had been passivated with hydrogen by etching in a NH4F solution. The multilayers were observed by STM, although not with atomic resolution. The conductivity type of the doped layers was determined as a function of position in the cross-section from current-voltage measurements.