EFFECTS OF ELECTRON AND ATOMIC-HYDROGEN IRRADIATION ON GAS-SOURCE MOLECULAR-BEAM EPITAXY OF DIAMOND WITH PURE METHANE

We investigated the effects of electron and atomic hydrogen irradiatio n on gas-source molecular beam epitaxy (GSMBE) of diamond with pure me thane (CH4). Irradiating the C(001) surface with a 200 eV electron-bea m at 800 degrees C enhanced the growth rate (GR) similar to 2-5 times over the method without irradiation. By using a CH4 beam decomposed by electron impact in addition to the electron-beam irradiation, the GR was enhanced by >100 times. However, the grown films contained an appr eciable amount of amorphous carbon. By contrast, irradiating the surfa ce with an atomic hydrogen beam enhanced the GR by about five-fold wit hout the concurrent growth of amorphous carbon. (C) 1997 Elsevier Scie nce S.A.