Title:
DIFFERENTIAL VIRTUAL GROUNDED BEAM BLANKER
Document Type and Number:
Japanese Patent JPH0773835
Kind Code:
A
Abstract:
PURPOSE: To remove the effect of an undesirable overcorrect by providing a double deflecting beam blanker with the first plate and the second plate in a specified configuration to compensate parallel current flows in reverse through a blanker voltage plate. CONSTITUTION: An eddy current is reduced by providing a double deflecting beam blanker with reverse parallel current flows. A voltage driver 109 supplies a negative voltage signal 105 to a blanker voltage plate 102 for creating a positive current flow through the blanker voltage plate 102 in the direction, as shown by an arrow mark 106. The current flow directions of the blanker voltage plate 102 is opposite to that of a virtual grounding plate 101 mutually. That is, reverse parallel flows to be place. The reverse parallel current flows nullify a resulting magnetic field 108 on the axial line and a magnetic field generated outside a blanker structure. No eddy current is generated in an adjacent conductor, resulting in the positional precision of beam at a target to be improved.
Inventors:
MAAKU EI GESUREI
DEIBUITSUDO EICHI KORUBII
DEIBUITSUDO EICHI KORUBII
Application Number:
JP4994494A
Publication Date:
March 17, 1995
Filing Date:
February 24, 1994
Export Citation:
Assignee:
ETEC SYSTEMS INC
International Classes:
G03F7/20; G21K5/04; H01J37/04; H01J37/09; H01J37/305; H01L21/027; (IPC1-7): H01J37/09; G03F7/20; G21K5/04; H01J37/305; H01L21/027
Attorney, Agent or Firm:
Tadashi Hagino (3 outside)
Next Patent: シート用カッタ装置