Medium energy (5-25 keV) 1 3 C + ion implantation into diamond (100) to a fluence ranging from 10 1 6 cm - 2 to 10 1 8 cm - 2 was performed for the study of diamond growth via the approach of ion beam implantation. The samples were characterized with Rutherford backscattering/channelling spectroscopy, Raman spectroscopy, X-ray photoemission spectroscopy and Auger electron spectroscopy. Extended defects are formed in the cascade collision volume during bombardment at high temperatures. Carbon incorporation indeed induces a volume growth but the diamond (100) samples receiving a fluence of 4 10 1 7 to 2 10 1 8 at. cm - 2 (with a dose rate of 5 10 1 5 at. cm - 2 s - 1 at 5 to 25 keV and 800 o C) showed no He-ion channelling. Common to these samples is that the top surface layer of a few nanometers has a substantial amount of graphite which can be removed by chemical etching. The rest of the grown layer is polycrystalline diamond with a very high density of extended defects.