Low-temperature electron transport on semiconductor surfaces

The low-temperature electron transport on semiconductor surfaces has been studied using an ultrahigh-vacuum, variable temperature scanning tunneling microscope (STM). The STM I(V) spectroscopy performed at various temperatures has made it possible to investigate the temperature dependence (300 K to 35 K) of the surface conductivity of three different semiconductor surfaces: highly doped n-type Si(100), p-type Si(100), and hydrogenated C(100). Low temperature freezing of specific surface electronic channels on the highly doped n- type Si(100) and moderately doped p-type Si(100) surfaces could be achieved, whereas the total surface conductivity on the hydrogenated C(100) surface can be frozen below only 180 K.