Document Type and Number:
Japanese Patent JPS5055270
Kind Code:
A
Abstract:
A square-shaped electron beam is stepped from one predetermined position to another to form a desired pattern on each chip of a semiconductor wafer to which the beam is applied. During various times, e.g., the target stage is moving mechanically from one chip to the next one, the electron beam is blanked. The blanking aperture plate in the electron beam column is provided with a second sensing aperture. During a blanked phase, the condensor lens images the electron source on the sensing aperture of the blanking aperture plate. A sensing plate disposed beneath the blanking aperture monitors the beam current and provides a signal to an alignment servo. Error correction is carried out by moving the beam in small increments in two orthogonal directions until the sensing plate reads a maximum current.
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Application Number:
JP8757674A
Publication Date:
May 15, 1975
Filing Date:
August 01, 1974
Export Citation:
International Classes:
H01J37/147; H01J37/244; H01J37/304; H01L21/027; (IPC1-7): G01R29/02