Patent ID: 7642530

Claim:
An ion implantation method comprising: irradiating a plurality of areas of a target substrate with ion beams from an ion irradiation unit, each of the ion beams reaching the substrate at a corresponding one incident angle; measuring the incident angle of each of the ion beams by an incident angle measuring instrument, wherein the incident angle measuring instrument comprises a first plate, a second plate located below the first plate, and charge measuring instruments located below the second plate; the first plate includes a first opening, a second opening, and a third opening located alone a first direction; the second plate includes a fourth opening corresponding to the first opening, a fifth opening corresponding to the second opening, and a sixth opening corresponding to the third opening; the first, the second and the third openings are smaller than the fourth, the fifth, and the sixth openings; the second opening and the fifth opening are centered at a same position so that the whole second opening overlaps the fifth opening; a center of the first opening is shifted to a center of the fourth opening in a second direction perpendicular to the first direction so that a part of the first opening overlaps the fourth opening; and a center of the third opening is shifted to a center of the sixth opening in an opposite direction to the second direction so that a part of the third opening overlaps the sixth opening; and changing a path of each of the ion beams so that a difference among the incident angles is set to within ±0.1° by a controller which controls the ion irradiation unit in accordance with information supplied from the incident angle measuring instrument.