Abstract: A method and system for controllably stripping a portion of silicon (98) from a silicon coated surface, for example, from an interior portion of an ion implanter (10). The system comprises (i) a source (80) of gas comprised at least partially of a reactive gas, such as fluorine; and (ii) a dissociation device (70) such as a radio frequency (RF) plasma source located proximate the silicon coated surface for converting the reactive gas to a plasma of dissociated reactive gas atoms and for directing the dissociated reactive gas atoms toward the silicon coated surface. A control system (102) determines the rate of removal of the silicon (98) from the surface by controlling (i) a rate of source gas flow into and the amount of power supplied to the dissociation device, and (ii) the time of exposure of the silicon coated surface to the plasma.