GA ON SI(112) - GROWTH AND ENERGETICS OF THERMAL-DESORPTION

The growth of Ga overlayers on Si(112) has been studied using Auger el ectron spectroscopy and low-energy electron diffraction. The feasibili ty of the (112) surface as a template for the growth of Ga quantum wel l wires is also explored. For substrate temperatures between room temp erature and 450-degrees-C we observe the Stranski-Krastanov growth mod e in which islands form on top of one to two overlayers. Above 450-deg rees-C a well-ordered overlayer structure yielding a (6 x 1) LEED patt ern is observed. Once this overlayer structure is formed there is litt le or no change in the AES signal or LEED pattern with increasing depo sition. Thermal desorption measurements from this overlayer coverage r eveal a much higher desorption energy than from either the Ga islands or from Ga on Si(111) and Si(001) substrates. These results suggest th at the Ga atoms are strongly bound in chains along the step edges of t he facet surface.