PROPERTIES OF (GA0.47IN0.53) AS EPITAXIAL LAYERS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY (MOVPE) USING ALTERNATIVE ARSENIC PRECURSORS

In this study, the use of novel, liquid, organic arsenic precursors as substitutes for the highly toxic hydride gas arsine (AsH3) in low pre ssure metalorganic vapor phase epitaxy (LP-MOVPE) of (GaIn)As lattice matched on InP has been investigated. The model precursors out of the classes of (alkyl)3-nAsH(n) (n = 0,1,2) are tertiarybutyl arsine (TBAs ), ditertiarybutyl arsine (DitBAsH) and diethyltertiarybutyl arsine (D EtBAs). The MOVPE growth has been investigated in the temperature rang e of 570-650 degrees C using V/III ratios from 2 to 20. The obtained e pitaxial layer quality as examined by means of optical and scanning el ectron microscopy (SEM), high resolution double crystal X-ray diffract ion, temperature-dependent van der Pauw-Hall, as well as photoluminesc ence (PL) measurements, will be compared for the different source mole cules. Under optimized conditions almost uncompensated n-type (GaIn)As layers with carrier concentrations below 1 x 10(15) cm(-3) and corres ponding mobilities above 80 000 cm(2)/V . s have been realized. For TB As and DitBAsH in combination with the corresponding P sources TBP and DitBuPH, respectively, we have worked out a process parameter area fo r the growth of layers with device quality, as proven by the realizati on of a pin-detector structure.