Systems, methods and computer program products for detecting the position of a new alignment mark on a substrate based on fitting to sample alignment signals

US6064486A · kind A · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Xun Chen · Tangxia, CN
• Amir A. Ghazanfarian · Stanford, US
• Mark A. McCord · Mountain View, US
• R. Fabian W. Pease · Stanford, US
• Thomas Kailath · Stanford, US

Key dates

• Filing date: May 21, 1998
• Grant date: May 16, 2000
• Expiry date: May 21, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F9/7076
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Systems, methods and computer program products detect a position of a new alignment mark on a substrate by producing an alignment signal model from sample alignment signals and fitting the new alignment signal to the alignment signal model. The alignment signal model may be produced from the multiple sample alignment signals using singular value decomposition, based on subspace decomposition of the alignment signals. By producing an alignment signal model from multiple sample alignment signals, asymmetries in the sample alignment marks and/or in the coatings that are fabricated on the sample alignment marks, may be taken into account when detecting the position of a new alignment mark.