Abstract: A plasma ion source including a plasma chamber, gas inlets, an RF antenna, an RF window, an extraction plate, a window shield, and a chamber liner. The RF window may be positioned intermediate the RF antenna and the plasma chamber. The window shield may be disposed intermediate the RF widow and the interior of the plasma chamber and the chamber liner may cover the interior surface of the plasma chamber. During operation of the ion source, the window shield sustains ionic bombardment that would otherwise be sustained by the RF window. Fewer impurity ions are therefore released into the plasma chamber. Simultaneously, additional dopant atoms are released from the window shield into the plasma chamber. Ionic bombardment is also sustained by the chamber liner, which also contributes a quantity of dopant atoms to the plasma chamber. Dopant ion production within the plasma chamber is thereby increased while impurities are minimized.