Electromagnetic electron reflector

An ion implantation system comprising:

• a plasmas ion source, an ion extractor, an analyzing electromagnetic, an electromagnetic electron reflector, an electron shower aperture and a target stage;
• and
• said electron reflector, comprising:
• an electrically conductive frame;
• permanent magnets within said frame and on opposite sides of said frame;
• an electrically conductive center aperture contained entirely within said frame and electrically isolated by first gaps from said frame and said permanent magnets and fixed in position by dielectric feed throughs passing through openings in a top and in a bottom of said frame, said dielectric feed throughs physically contacting a top and a bottom edge of said center aperture;
• first cup shields integrally formed on said top and bottom edges of said center aperture, said dielectric feed throughs nested within said first cup shields;
• second cup shields integrally formed on inside surfaces of said top and bottom of said frame, said second cup shields nested within respective first cup shields;
• electrically conductive entrance and exit apertures attached to said frame on opposite sides of said center aperture, said entrance and exit apertures electrically isolated from said center aperture by second gap;
• and
• an electrical conductor passing through at least one of said dielectric feed throughs and electrically contacting said center aperture.

A method of ion implanting semiconductor wafers comprising:

• providing an ion implantation system comprising a plasmas ion source, an ion extractor, an analyzing electromagnetic, an electromagnetic electron reflector, an electron shower aperture and a target stage, said electron reflector, comprising:
• an electrically conductive frame;
• permanent magnets within said frame and on opposite sides of said frame;
• an electrically conductive center aperture contained entirely within said frame and electrically isolated by first gaps from said frame and said permanent magnets and fixed in position by dielectric feed throughs passing through openings in a top and in a bottom of said frame, said dielectric feed throughs physically contacting a top and a bottom edge of said center aperture;
• first cup shields integrally formed on said top and bottom edges of said center aperture, said dielectric feed throughs nested within said first cup shields;
• second cup shields integrally formed on inside surfaces of said top and bottom of said frame, said second cup shields nested within respective first cup shields;
• electrically conductive entrance and exit apertures attached to said frame on opposite sides of said center aperture, said entrance and exit apertures electrically isolated from said center aperture by second gaps;
• and
• an electrical conductor passing through at least one of said dielectric feed throughs and electrically contacting said center aperture;
• passing an ion beam exiting said analyzing electromagnetic through said electromagnetic electron reflector while applying a voltage to said center aperture, said voltage sufficient to remove a sheath of electrons from said ion beam;
• passing said beam through said electron shower aperture;
• and
• impinging said beam from said electron shower on a semiconductor wafer.