Patent ID: 6867422

Claim:
An ion implantation apparatus comprising: an ion source section for generating ions; an ion implantation section for implanting said ions generated in said ion source section, in a substrate, a charged particle generator for generating charged particles having a charge opposite to that of said ions, the charge particle generator including a filament coil and a plasma generating chamber housing the filament coil; a beam guide section having an inlet aperture for accepting said ions from said ion source section, an outlet aperture for delivering said ions into said ion implantation section, a guide tube extending from said inlet aperture to said outlet aperture, and an introducing section having an opening thereof in an internal surface of said guide tube, for introducing said charged particles from said charged particle generator into said guide tube; and a shield section located between said opening of said introducing section and said outlet aperture, wherein the shield section has a portion adjacent the internal surface of said guide tube and the portion of the shield section is located at a position spaced away from said opening of said introducing section, and wherein said shield section comprises a shield surface making an acute angle with the internal surface of said guide tube.