Ion implantation method and ion implantation apparatus

An ion implantation apparatus which transports ions generated by an ion source to a wafer as an ion beam, causes the wafer to undergo wafer mechanical slow scanning and also causes the ion beam to undergo beam fast scanning in a direction perpendicular to a wafer slow scanning direction or causing the wafer to undergo wafer mechanical fast scanning in a direction perpendicular to a wafer slow scanning direction, irradiates the wafer with the ion beam by using the wafer slow scanning in the wafer slow scanning direction and the beam fast scanning of the ion beam in the direction perpendicular to the wafer slow scanning direction or the wafer fast scanning of the wafer in the direction perpendicular to the wafer slow scanning direction, the apparatus comprising:

• a beam measurement unit that measures a two-dimensional cross-sectional beam shape of the ion beam before ion implantation into the wafer;
• and
• a controller that defines an implantation and irradiation region of the ion beam by using the measured two-dimensional cross-sectional beam shape,
• wherein the controller makes the measured two-dimensional cross-sectional beam shape similar to an elliptical shape, sets an irradiation range of the ion beam by using a common tangent of an outer circumference of the elliptical beam and an outer circumference of the wafer, and thereby regulates the implantation and irradiation region.