Method for reducing an overlay error and measurement mark for carrying out the same

US7425396B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Stefan Gruss · Dresden, DE
• Detlef Hofmann · Dohnsen, DE
• Rainer Pforr · Dresden, DE
• Mario Hennig · Dresden, DE
• Guido Thielscher · Dresden, DE
• Hans-Georg Froehlich · Dresden, DE

Key dates

• Filing date: Sep 30, 2004
• Grant date: Sep 16, 2008
• Expiry date: Dec 19, 2026

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/143
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for reducing an overlay error of structures of a layer to be patterned relative to those of a reference layer includes formation of standard measurement marks assigned to one another in the two layers for determining an overlay error and for setting up further measurement marks for determining an additional optical imaging error of the projection system at least in the current layer. The further measurement marks have a geometry adapted to the geometry of selected structures of the circuit patterns to be transferred by projection from masks onto semiconductor substrates. An imaging error affects circuit structures and further measurement marks in the same way. An alignment correction for a subsequent exposure can be calculated from the measured positional deviations between the two standard measurement marks and between the standard measurement mark and the further measurement mark of the layer currently to be patterned.