Abstract: A chalcogenide such as As.sub.2 S.sub.3 is coated on a substrate at a very low rate of deposition in a vacuum evaporator and is coated with a thin silver layer. The silver coated layer is exposed to illumination in a quantity insufficient to form an etchable layer by conventional techniques and the silver is increased by treatment with a silver-containing agent capable of depositing silver on the image, preferably in the presence of radiation. NaAgSO.sub.3 is a presently preferred agent. The resulting image-bearing layer is photo-doped by exposure to band-gap radiation and the member is then etched.
Abstract: Surface sensitization of a chalcogenide glass is achieved by depositing an extremely thin silver layer, for example, by depositing a silver halide and developing and fixing in the absence of exposure. The sensitized chalcogenide can then be exposed to light to make it etch-resistant. Further exposure reverses the etch resistance, permitting positive or negative images and permitting erasure. Microlithographic resists such as masks can be formed.
Type:
Grant
Filed:
December 3, 1979
Date of Patent:
February 23, 1982
Assignee:
Ionomet Company, Inc.
Inventors:
Joseph I. Masters, Gershon M. Goldberg, Jerome M. Lavine
Abstract: A layer of a chalcogenide glass resist material, on a substrate on which a microlithographic pattern is to be formed, has a deposit of silver halide on its outer surface. By actinic irradiation a latent silver image replicating the desired pattern is formed in the silver halide deposit. This image is developed to a metallic silver, which is used to photodope the resist material for subsequent etching to produce the microlithographic pattern on the substrate. Positive and negative patterns are possible from the same starting laminate. One form of a microlithographic pattern is a mask for producing electronic circuits.