LOW-ENERGY SOLID INTENSE ION-BEAMS EXTRACTED BY ELECTRON-BEAM EVAPORATION ION-SOURCE FOR MATERIAL MODIFICATIONS

An investigation to reduce the energy of the solid ion beam extracted from electron beam evaporation ion source for material modifications h as been performed. The preliminary results have shown that the beam en ergy can be reduced to lower than 100 eV by a specially designed extra ction system for carbon and nitrogen mixed ion beams. The beam current extracted is up to 30 mA for a small 20 mm extraction diameter ion so urce. It has been found that the extraction energy can be controlled b y adjusting the bias voltage of the sample used for coating and the cr ucible potential, The extraction capability and the composition of the ion beam can also be controlled by changing the gas flow rate and the input power of the ion source. For carbon nitride films synthesized a t low energy by this system, the results have shown to exhibit very hi gh hardness values. The microhardness is over HK 6000 kg/mm(2). The pr inciple of this ion source is described. The structure of the ion sour ce, and the experimental results are also described in this article. ( C) 1998 American Institute of Physics. [S0034-6748(98)00407-9]