MOLECULAR-BEAM EPITAXIAL-GROWTH OF ARSENIDE PHOSPHIDE HETEROSTRUCTURES USING VALVED, SOLID GROUP-V SOURCES

The first arsenide/phosphide heterojunctions grown by conventional molecular-beam epitaxy with solid-source valved crackers are reported. The use of needle valves to switch the group V fluxes allows Ga0.52In0.48P/GaAs heterojunctions to be grown with virtually no intermixing between layers. Photoluminescence from quantum wells as narrow as 40 angstrom has also been observed. For comparison, conventional mechanical shutters were used to switch the group V fluxes, and the resulting layers were severely intermixed. The relative incorporation coefficients of the arsenic and phosphorous group V species were found to be temperature dependent, but there was no difference as a result of switching from tetrameric to dimeric arsenic.