Censor Patent- Und Versuchs-anstalt

Other

Herbert E Mayer

An apparatus for the projection copying of patterns defined by masks on a workpiece, e.g. a semiconductor wafer coated with a photoresist in the production of integrated circuit units, comprises a stage with a cross-feed for positioning a wafer chuck in the X and Y direction in a horizontal wafer plane at which the projection beam is focused. According to the invention, the stage is supported on a base plate which, in turn, is mounted on three spaced-apart posts capable of infinitesimal vertical adjustment, guide surfaces or lines between the base plate and the structure on which it is supported having normals some of which intersect substantially in the wafer plane so that the axis of tilt, which can be generated by differentially adjusting the posts, is located substantially in the wafer plane.

Apparatus for the projection copying of mask patterns on a workpiece

In the projection-copying of a mask on a workpiece including a light-reflecting semiconductor substrate, the alignment of mask and workpiece is effected by illuminating marks on the substrate which appear dark relative to a surrounding area. To provide each mark with a contrasting background of sufficient brightness, a partly reflecting surface layer overlying the substrate in that area has a nonuniform optical thickness whereby cancellation of reflections due to interference is limited to isolated regions.

Method of projecting printing on semiconductor substrate and workpiece

A device for the projection printing of the masks of a mask set onto a semiconductor substrate comprising a projection lens for imaging the patterns of said masks on photosensitive layers of said substrate. Alignment patterns are disposed said masks and alignment targets on said substrate. Said alignment patterns of at least one of said masks and said alignment targets of said substrate are positioned in non-conjugated areas in respect of the projection lens, i.e. in areas which cannot be imaged into one another by means of said projection lens. For the alignment process between said mask and said substrate auxiliary optical means are provided, said alignment targets of said substrate and said alignment patterns of said mask being imaged into one another by means of said auxiliary optical means.

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Eschen, Austria

Herbert E Mayer