MOVPE GROWTH OF SPONTANEOUSLY ORDERED (GAIN) AND (ALIN)P LAYERS LATTICE-MATCHED TO GAAS SUBSTRATES

A systematic study of the metal-organic vapour-phase epitaxial growth of (GaIn)P and (AlIn)P layers deposited on GaAs substrates with (001) and (110) orientation is presented. Special attention has been paid to the growth on (001)-oriented wafers with different misorientations to the growth direction. The influence of the growth conditions on the p roperties of the epitaxial layers such as lattice mismatch, alloy comp osition, photoluminescence (PL) wavelength, FWHMs of PL peaks and atom ic ordering is discussed. Layers with mirrorlike surfaces and various degrees of order could be deposited at growth temperatures T-g ranging from 595 degrees C to 750 degrees C for (GaIn)P and 720 degrees C to 800 degrees C for (GaIn)P. In addition to the influence of T-g on the Ga incorporation during the (GaIn)P growth we found the Ga distributio n coefficient k(Ga) to be affected by the misorientation of the substr ates. k(Ga) correlates presumably with the number of kinks and steps o n the substrate surface. Transmission electron diffraction (TED) and P L investigations show that the degree of order often described by the ordering paramter eta - depends strongly on T-g; the ordering is more pronounced when the layers are deposited on substrates misoriented tow ards the (<(1)over bar11>) lattice plane. Strong ordering has been obs erved for (GaIn)P samples grown at 680 degrees C on substrates 2 degre es misoriented towards the [<(1)over bar 10>] direction and at 650 deg rees C on substrates 6 degrees misoriented towards the same direction. For the (AlIn)P samples striking ordering has been found when they we re grown at 720 degrees C.