Automatic alignment for electron image projection

Summary form only given, as follows. The electron image projector described is capable of reproducing mask patterns with 1/2 μm wide lines over a 50 mm silicon slice. A particular attraction of the system is the caesium iodide photocathode which is relatively insensitive to contamination and is easy to prepare. A method of alignment of successive masks is described based on the Brehamstrahling X-rays that are generated whsn electrons strike a heavy metal marker on the slice. The Ae1tomatic Alignment equipment is described in some detail and results are presented showing resist patterns automatically aligned with respect to a marker to an accuracy of 0.1 μm.