DIRECT PROCESS FOR THE PRODUCTION OF CHROME MASKS WITH A PATTERN GENERATOR

摘要

Reticle patterns are formed upon a chrome-coated plate by means of forming a resist pattern upon the surface of the chrome having a predetermined thickness at which resonant absorption phenomenon occurs and a maximum rate of development is achieved. The resist layer should comply with the relationship where lambda is representative of the chosen wavelength of the light source used to expose the resist, n is representative of the index of refraction of the resist for that chosen wavelength, and k is an integer ranging from 0 to 4. Resists with such thicknesses establish stationary wave phenomena in order to permit use of very thin resist layers. The value of k should preferably be one, for a resist thickness of about 1800 A where n equals 1.63 and lambda is about 4050 A for xenon lamps. The resist is then exposed by a pattern generator, developed, and a positive or negative pattern is formed by means of etching or a lift-off technique, respectively.