Ion implantation method and ion implantation apparatus

An ion implantation apparatus comprising:

• a beam scanner;
• a reciprocation device that is provided at the downstream side of the beam scanner and reciprocates a wafer in a direction perpendicular to a beam scanning direction;
• a beam measurement unit that is able to measure an ion irradiation amount distribution in the beam scanning direction at a wafer position;
• and
• a control unit that outputs a control waveform to the beam scanner for scanning the ion beam in a reciprocating manner,
• wherein the control unit includes:
• an output unit that outputs a reference control waveform to the beam scanner;
• an acquisition unit that acquires the ion irradiation amount distribution measured for the ion beam scanned based on the reference control waveform from the beam measurement unit;
• and
• a generation unit that generates a correction control waveform by using the acquired ion irradiation amount distribution,
• wherein the reference control waveform is a control waveform for scanning the ion beam so that a scanning speed distribution indicating a change value of each beam position in time in the beam scanning direction at a wafer position becomes a first scanning speed distribution and a scanning period becomes a first scanning period,
• wherein the ion irradiation amount distribution indicates the distribution of the total ion irradiation amount of each beam position in the beam scanning direction at the wafer position when scanning the ion beam over the wafer a predetermined number of times in a reciprocating manner,
• wherein the correction control waveform is a control waveform for scanning the ion beam so that the scanning speed distribution becomes a second scanning speed distribution and the scanning period becomes a second scanning period,
• wherein the second scanning speed distribution is a scanning speed distribution for scanning the ion beam so that the ion irradiation amount distribution becomes a target distribution,
• wherein the second scanning period is a scanning period that is adjusted so that the ion irradiation amount distribution per unit time of the ion beam scanned by the second scanning speed distribution becomes a target value,
• wherein the generation unit includes a first calculation unit that calculates the second scanning speed distribution by using the first scanning speed distribution and the acquired ion irradiation amount distribution, and a second calculation unit that calculates the second scanning period by using the calculated second scanning speed distribution, and
• wherein the generated correction control waveform is output to the beam scanner, and the ion beam scanned based on the correction control waveform is irradiated to the wafer.