We have investigated the doping incorporation and activation of InP growth using metalorganic chemical vapor deposition on <100≳, <311≳B, and <110≳ InP substrates. Effects of orientation, growth temperature, and V/III fluxes were studied. The dopants used were Zn from dimethylzinc [(CH3)2Zn] and diethylzinc [(C2H5)2Zn], S from hydrogen sulfide [H2S], Si from silane [SiH4], and Sn from tetraethyltin [(C2H5)4Sn]. The incorporation and activation of thep‐type dopant Zn are elevated on the <311≳B and <110≳ planes, while the incorporation is suppressed for then‐type dopants (S, Si, and Sn). Then‐type dopant Sn has similar incorporation and activation on the various substrate orientations studied. Anomalous Zn doping on the higher order planes <311≳B and <110≳ lead to the Zn incorporation exceeding the solubility limit in InP. Incorporated Zn levels as high as 1.0×1019cm−3were measured, and the corresponding activated Zn level was as high as 5.4×1018cm−3on a <110≳ InP substrate. Interdiffusion of thep‐type dopant Zn into the S‐dopedn‐type InP substrate is inhibited by a high S‐doping level and segregates at the substrate–epilayer interface. If the S‐doping level is lower than the Zn concentration, then Zn diffuses deep into the substrate at a uniform level.