| 摘要 |
PURPOSE:To facilitate the partial centering in the middle of a beam path by providing three centering coils for centering an electron beam at predetermined positions and controlling their deflection directions in unison respectively. CONSTITUTION:Three centering coils 11, 12, 13 are provided on the electron beam path of an electron optics lens barrel used for an electron beam exposing device or the like, a beam is deflected by the first centering coil 11, the beam is deflected by the second centering coil 12 in the opposite direction to the above, and the beam is further deflected by the third centering coil 13 in the same direction as for the first coil 11, thereby the beam is corrected so that its orbit having passed the third coil 13 is made the same as that before the centering. Accordingly, the upper beam can be centered without affecting the axis of the lower beam, thus the centering can be performed easily and in a short time. |
