The thermal stability of GaAs(C)/InAs superlattices grown by metalorganic molecular beam epitaxy on InP substrates has been examined by Hall measurements, transmission electron microscopy, and high resolution x‐ray diffraction. These structures provide an ordered counterpart to a random In0.53Ga0.47As alloy, in which high concentration carbon doping is generally difficult to achieve. In a 43 period (23 Å GaAs/26 Å InAs) superlattice in which the GaAs was C‐doped and the InAs undoped an average hole concentration of 7×1019 cm−3 and hole mobility of 20 cm2 V−1 s−1 was achieved. Such structures are stable against rapid thermal annealing (10 s) up to 750 °C. An 850 °C/10 s anneal reduced the hole concentration to 1.5×1019 cm−3, accompanied by the onset of intermixing of the superlattice. The surface morphology of all but very thick (36 Å GaAs/40 Å InAs) period superlattice structures remained specular, even after 850 °C, 10 s annealing. These superlattices show properties suitable for use in a range of electronic and photonic devices, particularly InP‐based lasers and heterojunction bipolar transistors.