| 摘要 |
PURPOSE:To produce the titled ion beam dosage with high precision by a method wherein a probe current is converted into frequency using a part of primary ion beams to correct beam irradiating time at each deflecting point immediately referring to the data on the conversion. CONSTITUTION:Ion beam led out of a fluid metallic ion source 7 by an electrode 8 are limited by a throttle 9 to be focussed by lenses 6a, 6b for deflection by a deflector 5 in a vacuum chamber 101. The ion current Ip to the throttle 9 is linearized to be converted into frequency f while signals to be the clock 1' of pattern producer 1 are transmitted from photocouplers 11. When the beam stop clock number is assumed to be n, the beam dosage D=n/K and f=K.Ip therefore if Ip and f are measured to calculate a constant K and the beam stop clock number n is set up, D value shall be a constant not to be fluctuated even if the Ip is fluctuated during scanning process so that the dosage may be made constant to provided processing and implantation with high precision.
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