Si overlayers have been grown under ultrahigh vacuum conditions on GaP(100) single crystals by means of molecular beam epitaxy. For growth temperatures of 300 °C and higher (2×1) low‐energy electron diffraction patterns of the Si overlayers were seen at all overlayer thicknesses produced (8–10 000 A˚). By means of Auger electron spectroscopy segregation of P and Ga on top of the grown Si surface was measured. With Rutherford backscattering using ion channeling we found Si minimum channeling yields of 3% in the GaP:Si(100) heterostructures, which corresponds well to the yield of pure monocrystalline (100) Si. Two methods are described to eliminate the Ga and P segregation.