HIGH-ENERGY IMPLANTATION WITH HIGH-CHARGE-STATE IONS IN A VACUUM-ARC ION IMPLANTER

Ion implantation energy can in principle be increased by increasing th e charge states of the ions produced by the ion source rather than by increasing the implanter operating voltage, providing an important sav ings in cost and size of the implanter. In some recent work we have sh own that the charge states of metal ions produced in a vacuum are ion source can be elevated by a strong magnetic field. In general, the eff ect of both high are current and high magnetic field is to push the di stribution to higher charge states - the mean ion charge state is incr eased and new high charge states are formed. The effect is significant for implantation application - the mean ion energy can be about doubl ed without change in extraction voltage. Here we describe the ion sour ce modifications, the results of time-of-flight (TOF) measurements of ion charge state distributions, and discuss the use and implications o f this technique as a means for doing metal ion implantation in the mu lti-hundreds of keV ion energy range.