METAL-ION IMPLANTATION FOR LARGE-SCALE SURFACE MODIFICATION

Intense energetic beams of metal ions can be produced by using a metal vapor vacuum arc plasma discharge from which the ion beam is formed. We have developed a number of ion sources of this kind and have built a metal ion implantation facility which can produce repetitively pulsed ion beams with mean energy up to several hundred kilo electron volts, pulsed beam current of more than an ampere, and time averaged current of several tens of milliamperes delivered onto a downstream target. We have also done some preliminary work on scaling up this technology to very large size. For example a 50-cm diam (2000 cm2) set of beam formation electrodes was used to produce a pulsed titanium beam with ion current over 7 A at a mean ion energy of 100 keV. Separately, a dc embodiment has been used to produce a dc titanium ion beam with current over 600 mA, power supply limited in this work, and up to 6 A of dc plasma ion current was maintained for over an hour. We present here a review and summary of this metal ion implantation research program and describe some of the surface modification research that we have done with it.