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) an d dimethylethylaminealane (DMEAAl) for the metalorganic vapor phase ep itaxy (MOVPE) of (AlGa)As using the carrier gases hydrogen and nitroge n was studied. AlxGa1-xAs samples were deposited in the growth tempera ture range between 550 and 700 degrees C. Photoluminescence spectra fo r samples grown above 600 degrees C show only one peak, which is assig ned to the bound exciton transition. This documents that virtually no carbon is incorporated into the layers using the metalorganic source c ombination TEGa and DMEAAl. In addition, the new approach using the ca rrier 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.