A plasma containing both beryllium ions and beryllium fluoride ions is achieved. Beryllium crystals are used as a cathode in an ionization chamber containing boron trifluoride gas. The boron trifluoride gas and the beryllium are ionized to produce both beryllium fluoride ions (BeF.sup.+) and beryllium ions (Be.sup.+). Beryllium fluoride ions are emitted to impact a semiconductor target and where they divide thereby implanting beryllium and fluorine.