| 摘要 |
<p>A high dose rate, high impedance plasma ion implantation method and apparatus are disclosed. The method and apparatus apply high voltage pulses to a target cathode (6) within an ionization chamber (2) to both sustain a plasma in the gas surrounding the target (6), and to implant ions from the plasma into the target (6) during at least a portion of each pulse. Operating at voltages in excess of 50 kV that are too high for the reliable formation of a conventional glow discharge, the plasma is instead sustained through a beam-plasma instalibity interaction between secondary electrons emitted from target (6) and a background pulsed plasma. The voltage pulses are at least about 50 kV, and preferably 100 kV or more. Pulse durations are preferably less than 8 microseconds, with a frequency in the 50 - 1000 Hz range. The preferred gas pressure range is 1x10<-><4> - 1x10<-><3> Torr. Auxiliary electrodes (24a, 24b) can be used at the lower pressures to provide sufficient seed electrons for initiating a plasma, which is sustained by the beam-plasma instalibity interaction. <IMAGE></p> |
