METHOD OF FABRICATING DIFFRACTION GRATING MASTERS AND APPARATUS THEREFOR

摘要

A method of producing a diffraction grating master which comprises exposing a plurality of reduced first grating patterns on a light sensitive layer in conformance with a predetermined code; processing the light sensitive layer to produce first gratings therein; exposing a plurality of reduced second grating patterns on the light sensitive layer (superimposed on the first gratings) and repeating the processing step to produce the second gratings; vacuum depositing a layer of silver on the superimposed first and second gratings; electroplating a layer of nickel on the silver layer on the superimposed gratings; separating the resulting nickel-silver layer from the light sensitive layer; and reinforcing the nickel-silver layer (formed in the pattern of the first and second gratings) for use as an embossing master. A special electroplating fixture used in the electroplating step insures that the nickel layer being deposited lies flat without "peeling".