THE OPERATION OF METALORGANIC BUBBLERS AT REDUCED PRESSURE

Operating a metalorganic (MO) bubbler at low pressure allows a high flux of MO reagent to be extracted without resorting to high carrier gas flows. This approach is particularly suitable for the MOMBE (metalorganic molecular beam epitaxy) growth of III-V compounds. Using a “see-through” water bubbler, we have compared the theory and practice of reduced-pressure bubbler operation, both with and without a carrier flow. We conclude that the small carrier approach offers a wider flexibility in the choice of reagent flow, and a better stability and day to day repeatability of reagent flow. The reduced pressure operation of triethylgallium (TEGa) and triethylaluminum (TEA1) bubblers is described, in the context of the MOMBE growth of GaAs and AlAs. We show that using the small carrier flow approach, the reagent flow can be accurately controlled and predicted over a wide range. © 1990, American Vacuum Society. All rights reserved.