Method and Apparatus for Digital Control of E-Beam Pattern Writing as Applied to Subfield and Vector Equipment
Original Publication Date: 1980-Mar-01
Included in the Prior Art Database: 2005-Feb-13
Previous E-beam pattern writing has been accomplished by controlling the on/off state of the beam (path) while it was scanned repeatedly across the field by a separate deflection system. Rectangular geometries were developed using successive instructions defining blanked and unblanked portions of each line, as well as some fractional offset spot positioning. The function of the pattern digital hardware was therefore to expand that spot-related data and convert it to beam on/off control signals. Electrostatic corrections, deflections, and spot shape definition remained the responsibility of other systems.