A NEW APPROACH TOWARDS LOW-PRESSURE METALORGANIC VAPOR-PHASE EPITAXY OF (ALGA)AS USING TRIETHYLGALLIUM AND DIMETHYLETHYLAMINEALANE

The suitability of the metalorganic sources trimethylgallium (TEGa) and dimethylethylaminealane (DMEAAl) for the metalorganic vapor phase epitaxy (MOVPE) of (AlGa)As using the carrier gases hydrogen and nitrogen was studied. AlxGa1-xAs samples were deposited in the growth temperature range between 550 and 700 degrees C. Photoluminescence spectra for samples grown above 600 degrees C show only one peak, which is assigned to the bound exciton transition. This documents that virtually no carbon is incorporated into the layers using the metalorganic source combination TEGa and DMEAAl. In addition, the new approach using the carrier gas N-2 leads to increased homogeneity and higher quality AlxGa1-xAs layers at lower growth temperatures, and allows the employment of a factor of 2 lower V/III ratios.