AVS 46th International Symposium
    Surface Science Division Thursday Sessions
       Session SS2+EM+NS-ThM

Paper SS2+EM+NS-ThM6
The Role of Arsenic Surfactant in the Growth of Germanium Thin Films on Si(100) Surfaces

Thursday, October 28, 1999, 10:00 am, Room 607

Session: Nucleation and Growth
Presenter: C.L. Berrie, University of Colorado, Boulder
Authors: C.L. Berrie, University of Colorado, Boulder
J. Bright, University of Colorado, Boulder
S.R. Leone, University of Colorado, Boulder
Correspondent: Click to Email
The role of arsenic surfactant in the growth of germanium films on Si(100) substrates is investigated using laser single photon ionization time of flight mass spectrometry, reflection high energy electron diffraction, and atomic force microscopy. The energetics of arsenic interaction with Si(100) and Ge(100) are investigated by monitoring the temperature dependence of the desorbing fluxes of As@sub 4@, As@sub 2@ and As atoms from the substrate under a constant incident As@sub 4@ flux. These measurements indicate that the As@sub 2@ interactions with Si(100) and Ge(100) differ dramatically. In particular, the As@sub 2@ flux plateaus in the case of the Si(100) substrate from 800 K to 1000 K. In the case of the Ge(100) substrate, the As@sub 2@ flux monotonically increases over this temperature range and a similar plateau is not observed. Measurements of the desorbing As@sub n@ fluxes are also made during Ge growth on a Si(100) surface. The dramatic difference in the arsenic interaction on these two surfaces is evident in these measurements as well. The morphologies of the resulting films are monitored ex-situ using atomic force microscopy to determine the effect of arsenic coverage on the size and density distributions of islands formed. As the arsenic coverage is increases, the observed island size decreases and the density of islands increases dramatically. The mechanisms for the Ge growth and the interaction in the presence of the arsenic surfactant will be considered.