DEPOSITION BY LP-MOVPE IN THE GA-IN-AS-P SYSTEM ON DIFFERENTLY ORIENTED SUBSTRATES

We have studied the MOVPE of GaInAs and its binary constituents GaAs and InAs, and of GaInP and its binary constituents GaP and InP on InP, and on GaAs (100), (011), (111)A, (111)B oriented unmasked planar substrates in order to gain an understanding of the deposition on the bottom plane and on side wall facets of trenches in selective embedded growth. Temperature (940 K) and total pressure (20 hPa) were selected with this purpose in mind. It is shown that the behaviour of the binaries provides an understanding of the factors determining the deposition of the ternaries and that insights for selective growth on partially masked substrates can be gained from these data. In contrast to InP and InAs growth, the rates for the Ga binaries GaAs and GaP and the ternaries depend on the substrate orientation. The variation of the rates of the ternaries is very similar to that of the binary Ga constituents. More importantly, also the composition (Ga content) of the ternaries appears to track with this parameter and varies rather widely, particularly for GaInAs. In the case of selective embedded deposition the differences in rates between the different surfaces tend to be enhanced compared to those on unmasked substrates due to migration effects.