| 摘要 |
PURPOSE:To precisely and rapidly project electron beam by enhancing the current density corresponding to allowable blur amount specified in response to the size, shape and area of the beam. CONSTITUTION:Electron beam projected from an electron gun is turned ON or OFF by electrodes 4, and variously shaped through slits 5, deflectors 6, lens 7 and slits 8. The beam thus shaped is determined at its half angle via an aperture 9, and focused through a lens 10 and a deflector 11 on a specimen 12. The positions of the respective unit exposures of the beams are deflected by the deflector 11 through a DA converter 14 and a circuit 15 from the specified information of a memory 18. The size and shape of the beam is set by specifying a memory 16 and deflecting the beam by the deflector 6 via a DA converter 17 and a circuit 18. The exposure time is set by specifying a memory 19 to drive the electrodes 4 via a DA converter 20 and a circuit 21. Beam current density is set by specifying a memory 22 and altering the bias of a Wehnelt cylinder 2 via a DA converter 23 and a circuit 24. Thus, it can precisely and rapidly project electron beam. |
