| 摘要 |
PURPOSE:To obtain a stable pattern drawing by correcting horizontal beam deflection scanning to the vertical, according to the time difference when the position synchronizing pulses occur with respect to the deflection synchronization pulses and the vertical substrate movement. CONSTITUTION:When the vertical movement of the mask is faster than the set value, spaces occur to the horizontal beam pattern drawing. Therefore, the output from the D/A converter DAC-YP is used to correct the vertical deflector output to the positive direction in accordance with the adder ADD1 output. Thus, the entire beam deflection in the horizontal direction is corrected to the vertical direction to provide a stable pattern drawing. If the mask movement is slower than the set value, overlapping occurs to the horizontal pattern drawing. At this time the D/A converter DAC-YP output is used to correct the vertical deflector output to the positive direction, correcting the horizontal deflection to provide a stable pattern drawing. similarly, the reverse mask movement is corrected. Because the deflection synchronizing pulses are used, independent of the position synchronizing pulses, for horizontal deflection scanning, the pattern drawing time is reduced. |
