Ion implanter and ion implantation method

An ion implanter comprising:

• a beamline unit comprising:
• a beam deflector capable of deflecting an ion beam in an x direction;
• a beam scanner disposed downstream of the beam deflector and capable of deflecting the ion beam in the x direction in a reciprocating manner to scan the ion beam;
• and
• a beam collimator disposed downstream of the beam scanner and comprising a collimating lens that collimates the scanned ion beam in a z direction, the collimating lens having a focus at a scan origin of the beam scanner,
• wherein the beamline unit contains a reference trajectory of the ion beam, the z direction represents a direction along the reference trajectory, and the x direction represents a direction perpendicular to the z direction;
• and
• a controller that controls at least the beam deflector of the beamline unit,
• wherein the controller corrects an x-direction deflection angle in the beam deflector so that an actual trajectory of the ion beam deflected by the beam deflector intersects with the reference trajectory at the scan origin on an xz plane.