Browse Prior Art Database

Periodicity Tracking Interface

IP.com Disclosure Number: IPCOM000066279D
Original Publication Date: 1979-Feb-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Appolonia, MD DiFazio, J Hollenbeck, OF Lowry, R Zingerman, J [+details]

Abstract

Photorepeaters for generating exposure masks have a small computer to position the table under the lens for the exposure of each mask segment. The photorepeater uses a linear actuator to move the table and a laser gauge to determine the table position. The X and Y position data for each segment or chip, using the laser gauge, is recorded while the master mask is being stepped. The data is then used to calculate the following parameters: 1. Periodicity 2. Orthogonality 3. Straightness of travel 4. Overalls