摘要 |
<p>A sensor (110, 210) positioned relative to an ion beam (20) for use in an ion implantation system (10) for doping semiconductor wafers (41). The sensor allows relatively accurate determination of ion beam potential so that steps can be taken to minimize this potential. In a preferred design, a number of electrodes (130, 132) are positioned relative the ion beam and biased at control voltages which allow the ion beam potential to be determined. In one embodiment, the ion beam potential is used to control injection of neutralizing electrons into the ion beam. <IMAGE></p> |