Patent ID: 6583544
Filing Date: 2003-06-24
Classification: H01J

Abstract:
An ion source for an ion implanter, comprising:(i) an ionization chamber defined at least partially by chamber walls and having an inlet into which a sputtering gas may be injected, and an aperture through which an ion beam may be extracted; (ii) an ionizing electron source for ionizing the sputtering gas to form a sputtering plasma; (iii) a sputterable repeller for (a) repelling electrons emitted by said ionizing electron source, and (b) providing a source of sputtered material that can be ionized by said electron source, said sputterable repeller comprising a slug of sputterable material and a mounting structure for mounting said slug within said ionization chamber, said slug being removably detachable from said mounting structure, wherein said repeller is electrically isolated from said ionization chamber walls, and wherein said repeller is negatively biased with respect to said ionization chamber walls; (iv) a variable power supply for negatively biasing said repeller with respect to said ionization chamber walls; and (v) a controller for outputting a control signal to said repeller power supply to vary said negative bias based in part on a received ion beam current feedback signal.