Control system for a two chamber gas discharge laser

US6690704B2 · kind B2 · utility

Assignee

• Cymer, LLC · US

Inventors

• John P. Fallon · Andover, US
• Richard L. Sandstrom · Encinitas, US
• William N. Partlo · Poway, US
• Alexander I. Ershov · Escondido, US
• Toshihiko Ishihara · San Diego, US
• John Meisner · San Diego, US
• Richard M. Ness · San Diego, US
• Paul C. Melcher · El Cajon, US
• John Allen Rule · Berlin, US
• Robert N. Jacques · San Diego, US

Key dates

• Filing date: Jul 31, 2002
• Grant date: Feb 10, 2004
• Expiry date: Jul 31, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/2258
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Feedback timing control techniques are provided for controlling the relative timing of the discharges in the two chambers with an accuracy in the range of about 2 to 5 billionths of a second even in burst mode operation. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality.