GENERATION AND EVALUATION OF POST-HEATED ZINC AND SELENIUM MOLECULAR-BEAMS

We report the details of a post-heating cell developed to obtain high- velocity molecular beams. Zn and Se molecular beams generated from thi s cell are evaluated by measuring deposition rate by means of a quartz thickness monitor. The observed deposition rates are analyzed by mean s of a simple model for the operation of an ionization gauge. We found that Zn atoms have a thermal velocity determined by the temperature a t the post-heating zone, and that Se molecules are thermally cracked.