Showing papers on "Photomask published in 1970"

Holographically produced image arrays for photolithography

Abstract: This disclosure describes the generation of multiple identical images holographically. Wavefronts from a unit pattern and a pinhole array separately illuminated by branched, spatially filtered and collimated laser beams are Fourier-transformed and focused in front of a holographic medium. Illumination of the developed hologram with a laser beam conjugate to the wavefront from one of the pinholes produces a spaced array of real images of the unit pattern. The process is useful in photomask making, or as a way to directly expose photoresist in silicon device manufacture.

Laboratory Experiments in the Fabrication of Thick-Film and Thin-Film Integrated Circuits

Abstract: The thin-film and thick-film technology of fabricating hybrid integrated circuits has become of increasing importance as requirements for precision components, such as in active filters and digital to analog converters, are imposed on present circuit designs. This paper describes a series of experiments used to demonstrate this technology at the undergraduate level. The main objective of these experiments was to allow the undergraduate student to acquire a working knowledge of how the two hybrid integrated circuits were fabricated. A secondary objective was to allow him to evaluate the two techniques in terms of the equipment used and the electrical results obtained. In addition, the equipment and techniques used for monolithic I-C fabrication were introduced by these experiments. The methods used to fabricate photomasks, copper-beryllium evaporation masks, thick-and thin-film conductors, and resistors are described.