Patent attributes
A multi-column electron beam exposure apparatus includes: multiple column cells; an electron beam converging unit in which two annular permanent magnets and electromagnetic coils are surrounded by a ferromagnetic frame, the two annular permanent magnets being magnetized in an optical axis direction and symmetrical about the optical axis, where the electromagnetic coils adjust magnetic fields of the annular permanent magnets; and a substrate provided with circular apertures through which electron beams used in the column cells pass, respectively, where the electron beam converging unit is disposed in each of the circular apertures. The two annular permanent magnets may be disposed one above the other in the optical axis direction, and the electromagnetic coils may be provided inside or outside the annular permanent magnets in their radial direction.
