Apparatus for the projection copying of mask patterns on a workpiece
US4431304A · kind A · utility
Inventor
Key dates
| Filing date | Nov 25, 1981 |
| Grant date | Feb 14, 1984 |
| Priority date | — |
| Expiry date | Nov 25, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/682
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.