US 4,057,347 A · Optical exposure apparatus

Abstract

An improved optical exposure apparatus for use in exposing a workpiece to a desired light pattern with a high alignment accuracy and a high operational speed is disclosed. The apparatus comprises a moving table on which a workpiece to be exposed is disposed, a movable holder on which a mask having an original pattern is disposed, a light source for irradiating said mask, a reduction lens for projecting a reduced pattern of said original pattern onto said workpiece, means for positioning said moving table to a predetermined position, means for detecting the error of said table positioning, means for calculating a value of the error of positioning the workpiece divided by the reduction rate of the reduction lens, and means for automatically shifting said movable holder by the calculated value so as to cancel said error.

Claims5

Dependent claims

An optical exposure apparatus for exposing a workpiece to a reduced light pattern obtained from an original pattern through a projective lens having a reduction ratio smaller than one, comprising:

first means for generating a first control signal and for positioning the workpiece at a predetermined position in accordance with said first control signal;
second means for detecting an error in the actual positioning of the workpiece relative to the position represented by the first control signal generated by said first means and generating an error signal representative of said error;
and
third means, responsive to the error signal generated by said second means, representative of the error of positioning of the workpiece, for generating a second control signal and for automatically shifting the original pattern in accordance with said second control signal, so as to cancel the error.

1 more element

Dependencies are inferred from the claim text.

Optical exposure apparatus

Life of this patent

Optical exposure apparatus

Life of this patent

Abstract

Claims5