Phosphorus implantation was applied to the fabrication of mold-type diamond field-emitter arrays (FEAs) for the first time. The fabricated diamond FEAs were structurally and electrically investigated and the results were compared with those of flat diamond films under the same implantation conditions. When the diamond films were implanted after they were grown by microwave-plasma chemical vapor deposition (MPCVD), improved field emission characteristics were obtained. From previous work and these electrical results, it is possible to infer that implanted phosphorus ions collect around the Mo-diamond interface and give rise to enhancement of the field emission properties from Mo to vacuum through diamond. (C) 2003 Elsevier Science B.V. All rights reserved.