Ion implanter and ion implantation method

An ion implanter comprising:

• a beam generator that generates an ion beam;
• a beam scanner that performs reciprocating scan with the ion beam in a first direction;
• a platen driving device that performs reciprocating motion of a wafer in a second direction perpendicular to the first direction, while holding the wafer so that a wafer processing surface is irradiated with the ion beam subject to the reciprocating scan;
• and
• a control device that changes a beam scan speed in the first direction and a wafer motion speed in the second direction in accordance with a beam irradiation position in the first direction and the second direction at which the wafer processing surface is irradiated with the ion beam so that ions having a desired two-dimensional non-uniform dose distribution are implanted into the wafer processing surface,
• wherein the control device stores a plurality of implantation recipes, and each of the plurality of recipes includes a two-dimensional non-uniform dose distribution on the wafer processing surface, a plurality of correction functions determined based on a plurality of one-dimensional dose distributions in the first direction at a plurality of positions different in the second direction on the wafer processing surface, and correlation information associating the two-dimensional non-uniform dose distribution and the plurality of correction functions with each other,
• wherein in a case where the control device acquires a target pattern of the two-dimensional non-uniform dose distribution, the control device identifies the implantation recipe including the two-dimensional non-uniform dose distribution similar to the target pattern, from the plurality of implantation recipes, and
• wherein based on the plurality of correction functions and the correlation information which are included in the identified implantation recipe, the control device changes the beam scan speed in the first direction and the wafer motion speed in the second direction, and implants the ions having the two-dimensional non-uniform dose distribution similar to the target pattern, into the wafer processing surface.