Cymer, Inc.

Toshihiko Ishihara

William N Partlo

Alexander Igorevich Ershov

Richard M Ness

Robert N Jacques

John A Rule

Richard L Sandstrom

Paul C Melcher

John P Fallon

John Meisner

Richard G Morton

Thomas Hofmann

Herve A Besaucele

Palash P Das

Thomas Patrick Duffey

Jacob P Lipcon

Peter Clarke Newman

John T Melchior

Daniel Anthony Rothweil

Fedor Trintchouk

Igor Vladimirovich Fomenkov

Richard C Ujazdowski

Tom A Watson

Steven Merrill Harrington

Donald G Larson

Paul S Thompson

I Roger Oliver

Wayne J Dunstan

Robert A Shannon

Jean-Marc Hueber

James A Carmichael

Dmitry Berger

James H Azzola

Richard C Morton

Vladimir V Fleurov

Carl E Tedesco, Ii

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.

Control system for a two chamber gas discharge laser system

An apparatus and method which may comprise a seed laser defining an optical cavity producing an output. An amplifier may amplify the seed laser output. A bandwidth error signal generator may provide a bandwidth error signal from measured bandwidth and a target. A bandwidth selection element, which may comprise an adjustable sized aperture external to the cavity of the seed laser may selectively alter the bandwidth of the seed laser output. A bandwidth control system may control the bandwidth control element and also selectively adjust a differential firing time between the seed laser and amplifier or another bandwidth selection actuator to cooperated (coarsely or finely) with the bandwidth selection element to control bandwidth of the laser system.

Method and apparatus to control output spectrum bandwidth of MOPO or MOPA laser

A multi-chambered excimer or molecular halogen gas discharge laser system comprising at least one oscillator chamber and at least one amplifier chamber producing oscillator output laser light pulses that are amplified in the at least one power chamber, having a fluorine injection control system and a method of using same is disclosed, which may comprise: a halogen gas consumption estimator: estimating the amount of halogen gas that has been consumed in one of the at least one oscillator chamber based upon at least a first operating parameter of one of the least one oscillator chamber and the at least one amplifier chamber, and the difference between a second operating parameter of the at least one oscillator chamber and the at least one amplifier chamber, and estimating the amount of halogen gas that has been consumed in the other of the at least one oscillator chamber and the at least one amplifier chamber based upon at least a third operating parameter of the other of the at least one oscillator chamber and the at least one amplifier chamber, and producing an output representative of an estimated halogen gas consumption in the at least one oscillator chamber and of the halogen gas consumption in the at least one amplifier chamber, and a halogen gas injection controller determining the amount of halogen gas injection for the at least one oscillator chamber and the at least one amplifier chamber based upon the estimated fluorine consumption outputs from the fluorine consumption estimator and a cost function comprising a plurality of weighted injection decision determinations.

Multi-chambered excimer or molecular fluorine gas discharge laser fluorine injection control

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. Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) Finjection controls with novel learning algorithm.

Control system for a two chamber gas discharge laser

An automatic Flaser gas control, for a modular high repetition rate ultraviolet gas discharge laser. The laser gas control includes techniques, monitors, and processor for monitoring the Fconsumption rates through the operating life of the laser system. These consumption rates are used by a processor programmed with an algorithm to determine Finjections needed to maintain laser beam quality within a delivery range. Preferred embodiments include Fcontrols for a two-chamber MOPA laser system.

Automatic gas control system for a gas discharge laser

Reliable, modular, production quality narrow-band high rep rate ArF excimer laser

The present invention provides a very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. Very small quantities of a stablizing additive consisting of oxygen or a heavy noble gas (xenon or radon for KrF lasers, or krypton, xenon or radon for ArF lasers), are added to the gas mixture. Tests performed show substantial improvements in energy stability with the addition of about 30 ppm of xenon to a KrF laser. Tests show improved performance for the ArF lasers with the addition of about 6-10 ppm of Xe or 40 ppm of Kr. In a preferred embodiment very narrow bandwidth is achieved on a KrF laser by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line-narrowing module were replaced with calcium fluoride prisms.

Narrow band gas discharge laser with gas additive

A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.

Gas discharge laser with gas temperature control

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.

Reliable, modular, production quality narrow-band high rep rate F.sub.2

A coated ceramic insulator in a laser chamber that is exposed to a gaseous environment where impurities in the ceramic insulator are prevented from detrimentally contaminating the laser chamber by a high-purity insulating coating. The insulating coating prevents chemical interactions between the ceramic insulator and the gaseous environment. In particular, the coating prevents contamination, by impurities in the ceramic insulator, of the lasing gas.

Laser chamber incorporating ceramic insulators coated with dielectric

Narrow band excimer laser with gas additive

A very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. A prior art burst mode 'slug effect' occuring at one gas circulation time after the beginning of a burst of pulses is eliminated by the addition of a minute quantity of oxygen. In a preferred embodiment very narrow bandwidth is achieved by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line narrowing module were replaced with calcium fluoride prisms.

Narrow band excimer laser

Growing community of inventors

San Diego, CA, United States of America

Toshihiko Ishihara