Disappearing Alignment Marks for Election Beam Pattern Generation.

Alignment marks on x-ray lithography masks effectually disappear in semiconductor manufacture, a mylar substrate is covered with a 200 Angstrom gold film marks are 600 Angstroms thick, a layer of resist material covers the marks, fast alignment scans do not expose the resist so the pattern may be written over the marks gold is then electroplated on the holes formed in the exposed portions of the resist, the resist and 200 Angstrom gold layers are removed to leave the pattern and 600 Angstrom marks marks may be etched or left remaining depending upon the application. Author