Apparatus and methods for determining overlay of structures having rotational or mirror symmetry

• Main Author: GHINOVKER MARK
• Format: Patent
• Language: English
• Published: 20.03.2012
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Disclosed are overlay targets having flexible symmetry characteristics and metrology techniques for measuring the overlay error between two or more successive layers of such targets. Techniques for imaging targets with flexible symmetry characteristics and analyzing the acquired images to determine...