1 January 1994 Wafer steppers for the 64-M and 256-Mbit memory generations
Author Affiliations +
Abstract
Optical wafer steppers are used in the fabrication of submicron and subhalf micron integrated circuits. The SIA Technology Roadmap has outlined the major requirements steppers must meet for the 64M and 256Mbit memory generations. These include 0.35 μm and 0.25 μm resolution over 22 and 27 mm square image fields. This article outlines these requirements and explores the impact on wafer stepper design and use. Stepper cost of ownership will be considered including the contribution of the reticle to the overall cost of the process.

Two major trends can be discerned. First, the requirement of 0.25 μm imaging over fields larger than a square inch forces the adoption of step and scan technologies as the cost and size of full field lenses grow noncompetitive. Second, in order to reduce the overall cost of ownership of the photolithography process, the industry is adopting mix-and-match strategies using high NA steppers to print critical mask layers and high speed, low NA, wide field steppers to print non-critical layers.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
William H. Arnold, Gary C. Escher, "Wafer steppers for the 64-M and 256-Mbit memory generations", Proc. SPIE 10273, 64-to 256-Megabit Reticle Generation: Technology Requirements and Approaches: A Critical Review, 1027305 (1 January 1994); doi: 10.1117/12.177438; https://doi.org/10.1117/12.177438
PROCEEDINGS
40 PAGES


SHARE
RELATED CONTENT

EUV High NA scanner and mask optimization for sub 8...
Proceedings of SPIE (November 16 2015)
Defect dispositioning in a reticle qualification process
Proceedings of SPIE (March 11 2002)
Computer Optimized Mask Making
Proceedings of SPIE (August 08 1977)
Applications Of The Square Count Yield Model
Proceedings of SPIE (June 29 1984)
CD Control Issues In Submicron Optical Lithography
Proceedings of SPIE (September 17 1987)

Back to Top