Method and apparatus for ion beam neutralization

An ion implanter for treating one or more workpieces with positively charged ions comprising:

• a) an ion source for emitting positively charged ions from a source location;
• b) structure for forming an ion beam from the positively charged ions exiting the source;
• c) an ion treatment station for positioning the one or more workpieces to intercept the ions in the ion beam as they enter the ion treatment station;
• d) an ion beam neutralizer positioned upstream along the ion beam path from the treatment station of the one or more workpieces, said beam neutralizer comprising:
• i.) confinement structure bounding the ion beam path that defines an entrance plate and an exit plate to allow the ion beam to pass through a neutralization region before striking the one or more workpieces at the treatment station;
• ii.) an electron source for providing electrons within the neutralization region as the ion beam passes through the confinement structure;
• and
• iii.) an array of magnets supported by the confinement structure for setting up a magnetic field in the neutralization region that tends to confine electrons from the electron source within the confinement structure.