We present a new technique for providing nuclei for diamond formation on nondiamond substrates and its application to the growth of diamond on a Cu substrate by chemical vapor deposition (CVD). This is a predeposition process in which the substrate is immersed in a CH4/H-2 plasma formed by electron cyclotron resonance at a low pressure (0.1 Torr). The technique provides possibilities of nucleation over an increased area at temperatures lower (about 500-degrees-C) than usual, as well as improved process controllability. The grown diamonds on Cu exhibit a morphology significantly different from that of diamonds grown on Si.