Fixtures for Alignment and Exposure of Square or Rectangular Substrates Upon a Projection Printer
Original Publication Date: 1982-Oct-01
Included in the Prior Art Database: 2005-Feb-10
Perkin Elmer projection printers are normally used for exposing very small geometries in photoresist upon round silicon wafers in the fabrication of semiconductor products. The round wafer is held by vacuum upon a puck and brought up against an adapter ring which serves as a reference to determine an exact plane of focus for the instrument.