SYSTEM AND METHOD FOR CONTROLLING SPUTTERING AND DEPOSITION EFFECTS IN A PLASMA IMMERSION IMPLANTATION DEVICE

摘要

A plasma immersion ion implantation system (10) is provided for controlling the effects of sputtering and deposition during operation thereof. The system includes a chamber (12) for implanting wafers (W) positioned on a platen (14) therein with ions present in a plasma generated therein; a first power supply (33) for supplying a pulsed high voltage signal to the platen (14); a second power supply (46) for generating power necessary for igniting the plasma; a platen bias supply (56) for applying a bias voltage to the platen intermediate successive high voltage implant pulses; and a master implant controller (52). The master implant controller (52) simultaneously outputs a first control signal (72) to the second power supply (46) to ignite the plasma, and a second control signal (74) to a modulator (35) for applying a first of a series of high voltage implant pulses to the platen (14), so as to minimize the time the wafer (W) spends in the plasma prior to the first implantation pulse. The master implant controller further outputs a third control signal (76) for determining periods of time during which the successive high voltage implant pulses are applied to the platen. In addition, alternatively, (i) the master implant controller (52) further outputs a fourth control signal (78) for determining and varying periods of time intermediate times during which the successive high voltage implant pulses are applied to the platen, in response to a dose/current feedback signal, or (ii) the system (10) further includes a charge controller (54B) for outputting a bias control signal (84) for controlling the magnitude of the bias voltage applied to the platen (14) intermediate successive high voltage implant pulses.