Abstract: The present invention aims to extract a large electron beam and extend the service life of an electron source by effectively radiating an electron beam with low energy from a plasma chamber toward an ion extraction port, and optimally neutralizing space charges of ions in the vicinity of the ion extraction port. An electron source is installed behind a plasma chamber to control an extraction power supply, an electron accelerating power supply, and a lens power supply. Thereby, an electron beam is extracted from the power source, and accelerated. Then, the electron beam is carried through an electric field lens at a high speed, decelerated in the vicinity of the plasma chamber, then converged to radiate toward the ion extraction port. An aperture is installed at a crossover point of the electron beam to diminish backward flow of ionic gas from the plasma chamber to the electron source.

Abstract: There is disclosed an electron shower apparatus which eliminates the adverse effect of a magnetic field on electrons and which provides electrons in sufficient quantity when primary electrons having low energy are employed. In the apparatus, the magnetic field generated by a filament current is decreased or eliminated by pulsing the filament current or by passing a current opposite in direction to the filament current in the vicinity of the filament current.

Abstract: An ion implantation apparatus includes an ion source having an arc chamber generating ions and a drawing electrode drawing ions from the arc chamber, a mass separator transporting only ions desired for implantation, an ion implantation chamber in which the material to be implanted by ions is placed, and a controller means for automatically controlling the distance between the arc chamber and the drawing electrode incrementally in accordance with a theoretical calculation using normalized perveance considering the kind of ions to be implanted, the accelerating voltage, and the ion current and current density distribution.