| 摘要 |
PURPOSE:To make it possible to draw oblique figures with high speed and high accuracy characteristic by obtaining the triangular size-adjustable beam in addition to the rectangular adjustable beam through addition of the third rectangular aperture. CONSTITUTION:The electron beam irradiated from an electron gun 1 is formed into a square beam obliqued by 45 deg. by a first forming aperture 2 and when an overlapped figure of the second forming aperture 4 and irradiation beam is indicated by a constant output of a figure selection deflector 3, the beam becomes a rectangular equilateral triangle. A computer 14 drives a figure selection deflector drive circuit 11 in order to select an overlapped figure from a square or four bisectional rectangular equilateral triangles and generates a formed beam. Size of overlapped portion of the third forming aperture 7 and irradiation beam is changed by an output of a size designation deflector 6 and thereby the formed beam 8 of the adjustable size can be obtained. The size adjustable formed beam 8 is shifted to the irradiation position on the sample 10 by the irradiation position deflector 9 in order to expose the sample 10. |
