| 摘要 |
PURPOSE:To avoid a channeling phenomenon and implant ions uniformly by a method wherein a plurality of ion implantation processes whose respective relations between substrate crystals and ion implantation directions are crystallographically equivalent are applied to form one conductivity type layer. CONSTITUTION:Ions are implanted twice from two symmetrical directions expressed by points A1 and A3. By implanting ions twice from the directions which are crystallographically equivalent, the uniformity of ion implantation distribution can be excellent. More concretely, when a substrate 41 is turned within a predetermined angle range, a voltage of an AC source 46 only is applied to a beam scanning electrode 49 to apply an ion beam 44 to the substrate. If the substrate 41 is turned outside the predetermined angle range, a switching control means 48 applies both the AC source 46 voltage and a DC source 45 voltage to the beam scanning electrode 49 to deflect the ion beam 44 out of the substrate 41.
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