Use of multiple reticles in lithographic printing tools

US6628372B2 · kind B2 · utility

Inventors

• Andrew W. McCullough · Newtown, US
• Christopher Mason · Nashville, US
• Louis John Markoya · Sandy Hook, US
• Harry Sewell · Ridgefield, US

Key dates

• Filing date: Feb 16, 2001
• Grant date: Sep 30, 2003
• Expiry date: May 26, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70733
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A reticle stage having a range of motion sufficient to scan at least two distinct reticles. In a photolithographic process, a reticle stage having an extended range of motion and containing at least two reticles, preferably a phase shift reticle and a trim reticle, is used. The reticle stage scans the two reticles across an illumination field. The image of each reticle is projected by projection optics onto a photosensitive substrate on a wafer stage. The field on the photosensitive substrate is exposed with the image of the first reticle and subsequently exposed with the image of the second reticle. The projection of an image of a first and second reticle onto the same field in a scanning operation greatly facilitates throughput of the photolithographic tool or device. Reticle changes are eliminated when at least two reticles are needed to expose a single field. The use of multiple reticles to expose a single field is necessary when a phase shift mask and related trim mask are used. In another embodiment, the reticle stage has a range of motion permitting scanning of an additional calibration reticle. This permits rapid real time system calibration.