the service lifetime of an ion source is enhanced or prolonged by the source having provisions for in - situ etch cleaning of the ion source and of an extraction electrode , using reactive halogen gases , and by having features that extend the service duration between cleanings . the latter include accurate vapor flow control , accurate focusing of the ion beam optics , and thermal control of the extraction electrode that prevents formation of deposits or prevents electrode destruction . an apparatus comprised of an ion source for generating dopant ions for semiconductor wafer processing is coupled to a remote plasma source which delivers f or cl ions to the first ion source for the purpose of cleaning deposits in the first ion source and the extraction electrode . these methods and apparatus enable long equipment uptime when running condensable feed gases such as sublimated vapor sources , and are particularly applicable for use with so - called cold ion sources . methods and apparatus are described which enable long equipment uptime when decaborane and octadecaborane are used as feed materials , as well as when vaporized elemental arsenic and phosphorus are used , and which serve to enhance beam stability during ion implantation .