IMPROVED COMPOSITION HOMOGENEITY DURING SELECTIVE-AREA EPITAXY OF GAINAS USING A NOVEL IN PRECURSOR

GaInAs layers were grown selectively on partially masked InP substrate s by metalorganic vapor phase epitaxy using the conventional In precur sor trimethyl-indium (TMI) and the intramolecularly saturated compound dimethylaminopropyl-dimethyl-indium (DADI) for comparison. We obtaine d for both TMI and DADI an excellent morphology of the selectively gro wn structures. Significant differences between the two In sources were determined for the unwanted nucleation on the masked area and for the homogeneity of the composition of the grown ternary material. We attr ibute this observation to the higher chemical stability of DADI and a changed decomposition behavior, which leads to longer effective diffus ion lengths for DADI and its thermally decomposed fragments in the gas phase.