Layout impact reduction with angled phase shapes

US7135255B2 · kind B2 · utility

Assignees

• International Business Machines Corporation · US
• Infineon Technologies North America Corp. · US

Inventors

• Scott Bukofsky · Hopewell Junction, US
• John K. DeBrosse · Colchester, US
• Marco Hug · South Burlington, US
• Lars Liebmann · Poughquag, US
• Daniel J. Nickel · Colchester, US
• Juergen Preuninger · Munich, DE

Key dates

• Filing date: Mar 31, 2003
• Grant date: Nov 14, 2006
• Expiry date: Dec 27, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F1/30
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A phase shift mask shape that reduces line-end shortening at the critical feature without changing layout size increases required of requisite phase shift rules. The phase feature is given an angled extension, which includes the lithographic shortening value. This allows the critical shape to be designed much closer to the reference layer then it could without the angled extension feature. Phase mask extension features beyond a given device segment are significantly reduced by lengthening the feature along an uncritical portion; moving the feature reference point to the device layer; and flattening the phase extension feature into an L-shape or T-shape along the uncritical parts of a device segment. Applying these design rules allows a draw of the gate conductor under current conditions and puts phase shapes inside without extending the gate conductor dimensions to the next feature.