Censor Patent- Und Versuchs-anstalt

Other

Ernst W Loebach

Herbert E Mayer

Harry L Sawatzki

A projection mask and method and apparatus for production thereof comprising a substrate carrying a mask thereon, a cover glass covering the pattern mask and sealed at peripheral edges thereof to the substrate defining a space between the substrate with the mask and the cover glass. A particle-free fluid is provided in this space. A projection printing system projects illumination through such a projection mask into a light sensitive substrate.

Projection mask as well as a method and apparatus for the embedding

In a method for the projection printing of masks onto a wafer coated with a photosensitive layer, said mask and said wafer being aligned by imaging alignment patterns of said mask onto said wafer by means of alignment light. In order to obtain a high-intensity and high-contrast alignment signal generated by plotting said alignment light reflected from said wafer, said alignment light comprises at least two narrow wavelength ranges spaced from each other on the wave length scale, in said ranges said photosensitive layer of said workpiece being non-sensitive or low-sensitive, determining the intensity of said alignment light reflected from said workpiece and generating an alignment signal from the wavelength range of said alignment light having highest intensity.

Method for the projection printing

A method and device for the projection printing of a mask onto a workpiece, particularly onto a semiconductor substrate, said mask being illuminated by means of a light source and imaged on said workpiece by means of a projection lens, said workpiece being coated with a photoresist.

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Eschen, Liechtenstein

Ernst W Loebach