We present an investigation of the growth of InP based materials in a Multiwafer Planetary Reactor(R). A reactor suited for the simultaneous growth of 15 x 2 '', 8 x 3 '' or 5 x 4 '' wafers was used to grow InP, GdInAs and various GaInAsP compositions. As predicted by the theory of the Planetary Reactor(R) principle, excellent uniformities of all layer properties were found. Without any tuning of process parameters, thickness variations of +/-1% or better were obtained. The compositional uniformity was also very good. This was confirmed by X-ray diffraction and PL mapping. Emission wavelength uniformities were in the 1 nm range. P-and n-type doping was also investigated. Sheet resistivity measurements on doped samples reveal uniformities around 1%.