Paper
1 August 1992 Alignment mark detection using signed-contrast gradient edge maps
John Raymond Jordan III
Author Affiliations +
Proceedings Volume 1661, Machine Vision Applications in Character Recognition and Industrial Inspection; (1992) https://doi.org/10.1117/12.130304
Event: SPIE/IS&T 1992 Symposium on Electronic Imaging: Science and Technology, 1992, San Jose, CA, United States
Abstract
Fast, accurate alignment plays an important role in microelectronics manufacturing. As a result, the automation of alignment mark detection via image processing algorithms has been widely investigated. Algorithms for automatic alignment mark detection traditionally fall into one of two classes -- correlation-based or contour-based. Despite considerable success in these investigations, current algorithms are often time-consuming and sensitive to changes in illumination and rotation. In this paper, a novel algorithm for detecting alignment marks in grey-level images is presented. The fundamental advantage of this algorithm is the use of signed-contrast gradient edge maps, which represent intensity edges in terms of locally normalized intensity gradients. Appropriate use of these signed-contrast gradient edge maps yields alignment mark detection which is faster and more robust than traditional methods such as normalized cross-correlation. The efficacy of this algorithm is demonstrated by applying it to the automatic detection and location of alignment marks for semiconductor wafer alignment and directly comparing its performance against that of normalized cross-correlation in terms of accuracy, invariance to changes in mark rotation, and algorithm speed.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
John Raymond Jordan III "Alignment mark detection using signed-contrast gradient edge maps", Proc. SPIE 1661, Machine Vision Applications in Character Recognition and Industrial Inspection, (1 August 1992); https://doi.org/10.1117/12.130304
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Detection and tracking algorithms

Quantization

Tolerancing

Optical alignment

Image processing

Target detection

Edge detection

Back to Top