Narrow band laser with fine wavelength control

US6192064A · kind A · utility

Assignee

• Cymer, LLC · US

Inventors

• John M. Algots · San Diego, US
• Christopher A. Marchi · San Diego, US
• Frederick Erie · Oceanside, US
• Jesse Buck · San Marcos, US
• Alexander I. Ershov · Escondido, US
• Palash P. Das · Vista, US
• Igor V. Fomenkov · San Diego, US

Key dates

• Filing date: Dec 22, 1999
• Grant date: Feb 20, 2001
• Expiry date: Dec 22, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/2256
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A smart laser having automatic computer control of pulse energy, wavelength and bandwidth using feedback signals from a wavemeter. Pulse energy is controlled by controlling discharge voltage. Wavelength is controlled by very fine and rapid positioning of an R.sub.MAX mirror in a line narrowing module. Bandwidth is controller by adjusting the curvature of a grating in the line narrowing module. Preferred embodiments include automatic feedback control of horizontal and vertical beam profile by automatic adjustment of a prism plate on which beam expander prisms are located and automatic adjustment of the R.sub.MAX tilt. Other preferred embodiments include automatic adjustment of the horizontal position of the laser chamber within the resonance cavity. In preferred embodiments, feedback signals from a wavelength monitor are used to position the R.sub.MAX mirror. In other preferred embodiments a separate laser beam reflected off the R.sub.MAX mirror on to a photodiode array is used to position the mirror.