Paper
7 June 1996 Micrascan adaptive x-cross correlative independent off-axis modular (AXIOM) alignment system
Stan Drazkiewicz, Gregg M. Gallatin, Joe Lyons
Author Affiliations +
Abstract
As optical lithography approaches the 0.25 micrometers performance level, overlay performance approaches 75 nanometers (nm). This in turn requires alignment systems to work to tighter budgets. This paper presents the theory of operation behind the AXIOM off-axis alignment system. We have examined the advantages of using the AXIOM system, and have implemented a trade-off strategy. Our discussion includes an overview of the AXIOM alignment sensor head (sensor head) system. We also provide the benefits of the sensor's broadband incoherent light source illumination when used to achieve process insensitivity. In addition, we provide the benefit of being a bright and dark field system. We performed modeling to evaluate how various alignment targets interact with illumination. Modeling assessments highlighted the advantages of separately detecting the left and right diffracted order of a target. The sensor head can examine a target by using both bright field, left and right orders simultaneously. Examining a target helps us obtain more information and further reduces process sensitivity. Finally, we verified performance with multilevel data and compared it to industry standards.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Stan Drazkiewicz, Gregg M. Gallatin, and Joe Lyons "Micrascan adaptive x-cross correlative independent off-axis modular (AXIOM) alignment system", Proc. SPIE 2726, Optical Microlithography IX, (7 June 1996); https://doi.org/10.1117/12.240980
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Optical alignment

Semiconducting wafers

Sensors

Signal detection

Head

Signal processing

Light scattering

RELATED CONTENT

Computational scanner wafer mark alignment
Proceedings of SPIE (March 30 2017)
Alignment technique using wafer rear surface
Proceedings of SPIE (June 01 1992)
Autoalignment In Step-And-Repeat Wafer Printing
Proceedings of SPIE (July 17 1979)

Back to Top