| 摘要 |
PURPOSE:To largely improve the exposing accuracy by calculating the internal insertion correcting amount in response to a position by the correcting amount of four lattice points surrounding a deflecting position to correct a beam at the beam deflecting time to expose it. CONSTITUTION:When the more significant bit information DDM of beam deflecting position information is generated by a generator 3 on the basis of pattern information PD and input to a memory 2, the correcting amount information CD of four lattice points surrounding the deflecting position is accessed to calculate the deflecting position correcting amount (interpolating amount)CDf1 corresponding to the entire bit information DC and a throttle interpolating amount CDf2 by an internal insertion calculator 9. The amount CDf1 is added or sybstracted by an adder/subtractor 4 to the information DD, the interpolated position information CDF is D/A-converted by a D/A converter 5b, amplified by an amplifier 6b, and applied to a deflecting system. The signal CDf2 is D/A-converter by a D/A converter 5b, amplified by an amplifier 6a, and applied to a throttle correcting coil. The interpolating amount of the position B with a lattice point G00 as a reference point is calculated from the coordinates of the correcting amount f, the lattice point distance l and the position B of four lattice points G. According to this configuration, accurate pattern drawing can be formed without increasing the memory amount. |
