INFLUENCE OF HCL ON THE CHEMICAL-VAPOR-DEPOSITION AND ETCHING OF GE ISLANDS ON SI(001)

When HCl is added during the growth of Ge islands on Si(001) by chemic al vapor deposition, the reduced Ge surface diffusion impedes island d evelopment. There is a shift in the relative populations of different island types even when other conditions such as temperature, coverage, and growth rate, are unchanged. The effect of HCl on the net rate of deposition is proportional to the square of the HCl partial pressure, suggesting a surface reaction with the Ge. When larger islands are etc hed with HCl at high enough temperature, they revert to a shape charac teristic of smaller islands, confirming the reversibility of transform ations from one island type to another. It has not proved possible to use etching to produce smaller and more uniform islands. (C) 1998 Amer ican Institute of Physics. [S0003-6951(98)03039-3].