Reliable. modular, production quality narrow-band KRF excimer laser

US5991324A · kind A · utility

Assignee

• Cymer, LLC · US

Inventors

• David S. Knowles · San Diego, US
• James H. Azzola · San Diego, US
• Herve A. Besaucele · San Diego, US
• Palash P. Das · Vista, US
• Alexander I. Ershov · Escondido, US
• Igor V. Fomenkov · San Diego, US
• Tibor Juhasz · San Clemente, US
• Robert G. Ozarski · Livermore, US
• William N. Partlo · Poway, US
• Daniel A. Rothweil · San Diego, US
• Richard L. Sandstrom · Encinitas, US
• Richard C. Ujazdowski · Poway, US
• Tom A. Watson · Carlsbad, US
• Richard M. Ness · San Diego, US

Key dates

• Filing date: Mar 11, 1998
• Grant date: Nov 23, 1999
• Expiry date: Mar 11, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/1392
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A reliable, modular, production quality narrow-band KrF excimer laser capable of producing 10 mJ laser pulses at 1000 Hz with a bandwidth of about 0.6 pm or less. The present invention is especially suited to long-term round-the-clock operation in the lithographic production of integrated circuits. Improvements over prior art lasers include a single upstream preionizer tube and acoustic baffles. A preferred embodiment includes reduced fluorine concentration, an anode support bar shaped to reduce aerodynamic reaction forces on blower bearings, a modified pulse power system providing faster pulse rise time, an output coupler with substantially increased reflectivity, a line narrowing module with CaF prism beam expanders, a more accurate wavemeter, a laser computer controller programmed with new and improved pulse energy control algorithm.