Ion implanter and ion implantation method

An ion implanter comprising:

• a high energy multi-stage linear acceleration unit including a plurality of linear acceleration units, wherein each of the linear acceleration units includes high frequency accelerators respectively in a plurality of stages;
• and
• a control device controlling an operation of the high energy multi-stage linear acceleration unit in accordance with a data set defining a voltage amplitude, a frequency, and a phase of the high frequency accelerator in each of the plurality of stages,
• wherein the control device is configured to
• acquire a first data set for setting beam energy of an ion beam output from the high energy multi-stage linear acceleration unit to be a first output value,
• determine a second data set for setting the beam energy of the ion beam output from the high energy multi-stage linear acceleration unit to be a second output value different from the first output value, based on the first data set, and
• operate the high energy multi-stage linear acceleration unit in accordance with the determined second data set, and
• the control device determines the second data set so that an acceleration phase of the high frequency accelerator in each of the plurality of stages in at least one linear acceleration unit of the plurality of linear acceleration units is the same between the first data set and the second data set, in all of the high frequency accelerators respectively in the plurality of stages, and so that the voltage amplitude of the high frequency accelerator in at least one of the plurality of stages is different between the first data set and the second data set.