Hayes, Soloway, Hennessey, Grossman & Hage, P.C.
Electron-beam exposure system
 An electron-beam exposure system is constructed using electromagnetic lenses, apertures and an electron-beam mask, which are arranged and aligned in line between an electron source and a substrate. Within a trajectory of an electron beam that is radiated from the electron source and is then irradiated onto the substrate, crossover planes emerge with respect to electrons of the electron beam. The electron-beam mask is arranged at one crossover plane, while the aperture is arranged at another crossover plane. In addition, one aperture is an object aperture that narrows down the electron beam in sectional shape and size. The electron source is designed to bring a specific electron-beam intensity distribution in which electrons corresponding to periphery in section of the electron beam is made higher in intensity than electrons corresponding to a center portion in section of the electron beam, wherein a zonal-annular projection portion is formed to surround a center portion of a radiation surface of the electron source. To perform oblique illumination in which the electron beam is incident on the substrate in an oblique manner, the system is equipped with a modified object aperture, at the crossover plane, which is constructed by a center shield member for cutting off electrons having small beam incident semi-angles and a ring opening portion for selectively transmitting electrons having large beam incident semi-angles. Thus, it is possible to reduce Coulomb effect, and it is possible to improve resolution and throughput in manufacture of integrated circuits. 
NEC Corporation
B H H H B
B82Y H01J H01J H01J B82Y
inventional inventional inventional inventional inventional
Hiroshi
Yamashita