Fast wavelength correction technique for a laser

US6529531B1 · kind B1 · utility

Assignee

• Cymer, LLC · US

Inventors

• George J. Everage · San Diego, US
• Igor V. Fomenkov · San Diego, US
• Palash P. Das · Vista, US
• Richard L. Sandstrom · Encinitas, US
• Frederick Erie · Oceanside, US
• John M. Algots · San Diego, US

Key dates

• Filing date: Jun 19, 2000
• Grant date: Mar 4, 2003
• Expiry date: Feb 17, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/134
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Electric discharge laser with fast chirp correction. Fast wavelength chirp correction equipment includes at least one piezoelectric drive and a fast wavelength detection means and has a feedback response time of less than 1.0 millisecond. In a preferred embodiment a simple learning algorithm is described to allow advance tuning mirror adjustment in anticipation of the learned chirp pattern. Techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver. In another preferred embodiment chirp correction is made on a pulse-to-pulse basis where the wavelength of one pulse is measured and the wavelength of the next pulse is corrected based on the measurement. This correction technique is able to function at repetition rates as rapid as 2000 Hz and greater.