Cymer, Inc.

Cymer Laser Technologies

Stuart L Anderson

William N Partlo

Richard L Sandstrom

Igor Vladimirovich Fomenkov

Richard M Ness

Palash P Das

Richard C Ujazdowski

Daniel J W Brown

Alexander Igorevich Ershov

Herve A Besaucele

Eckehard D Onkels

Scott T Smith

David Wayne Myers

David S Knowles

William G Hulburd

Jeffrey Oicles

John Martin Algots

Ronald L Spangler

Xiaojiang Jason Pan

Paul C Melcher

Helmut Schillinger

Curtis L Rettig

Robert A Shannon

Brett D Smith

Claus Strowitzki

Scot T Smith

Alex P Ivaschenko

Shahryar Rokni

Robert B Saethre

Vladimir A Kulgeyko

Stephan Geiger

David M Johns

Tobias Pflanz

Claudia A Hartmann

Jennan Yu

Robert N Jacques

Peter Clarke Newman

Thomas Patrick Duffey

Daniel L Birx

Thomas D Steiger

Vladimir B Fleurov

I Roger Oliver

Gamaralalage G Padmabandu

Raymond F Cybulski

James K Howey

Jean-Marc Hueber

Paolo Zambon

Frederick A Palenschat

George J Everage

Mark Branham

Christian J Wittak

Clay C Titus

David W Meyers

Jerome A Emilo

Sunjay Phatak

Plash P Das

An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected laser output light pulse beam pulse produced by said gas discharge laser system by controlling the timing of the occurrence of the gas discharge between the first pair of electrodes and the occurrence of the gas discharge between the second pair of electrodes.

Very narrow band, two chamber, high rep-rate gas discharge laser system

An automatic gain control circuit in the feedback path for a laser wavelength control circuit is described herein. This gain control circuit automatically adjusts the amplification of the analog signals output from a photodetector array, where the array detects a fringe pattern created by a laser beam. Another feature of the preferred embodiment feedback circuit is the automatic setting of a DC offset voltage that compensates for errors in the feedback path and enables an accurate determination of a dark level signal in the fringe pattern signal. This dark level signal provides a reference for measuring the magnitude of the fringe pattern signal. Varying photodetector outputs may now be more accurately measured. The preferred embodiment feedback circuit also employs a very fast amplifier anti-saturation circuit using LED's connected in a clamp circuit.

Control circuit with automatic DC offset

A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an Fgas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.

High repetition rate gas discharge laser with precise pulse timing control

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in an ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between pulses. The master oscillator is equipped with a line narrowing package having a very fast tuning mirror capable of controlling centerline wavelength on a pulse-to-pulse basis at repetition rates of 4000 Hz or greater to a precision of less than 0.2 pm.

Very narrow band, two chamber, high reprate gas discharge laser system

The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Four KHz gas discharge laser system

Four KHz gas discharge laser

Very narrow band, two chamber, high rep rate gas discharge laser system

A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.

An electric discharge laser with fast wavelength correction. Fast wavelength correction equipment includes at least one piezoelectric drive and a fast wavelength measurement system and fast feedback response times. In a preferred embodiment, equipment is provided to control wavelength on a slow time frame of several milliseconds, on a intermediate time from of about one to three millisecond and on a very fast time frame of a few microseconds. Techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver for tuning the laser wavelength using a tuning mirror. A preferred control technique is described (utilizing a very fast wavelength monitor) to provide the slow and intermediate wavelength control and a piezoelectric load cell in combination with the piezoelectric driver to provide the very fast (few microseconds) wavelength control.

Laser wavelength control unit with piezoelectric driver

A gas discharge laser capable of operating at pulse rates in the range of 4,000 Hz to 6,000 Hz at pulse energies in the range of 5 mJ to 10 mJ or greater. Important improvements over prior art designs include: (1) a laser chamber having a gas flow path with a gradually increasing cross section downstream of the discharge electrodes to permit recovery a large percentage of the pressure drop in the discharge region, (2) a squirrel cage type fan for producing gas velocities through the discharge region of more than 76 m/s and capable of continuous trouble-free operation for several months, (3) a heat exchanger system capable of removing in excess of 16 kw of heat energy from the laser gas (4) a pulse power system capable of providing precisely controlled electrical pulses to the electrodes needed to produce laser pulses at the desired pulse energies in the range of 5 mJ to 10 mJ or greater at pulse repetition rates in the range of 4,000 Hz to 6,000 Hz or greater and (5) a laser beam measurement and control system capable of measuring pulse energy wavelength and bandwidth on a pulse-to-pulse laser with feedback pulse-to-pulse control of pulse energy and wavelength.

Extreme repetition rate gas discharge laser

Laser wavelength control circuit having automatic DC offset and gain

A laser light beam is processed in a first optical path to produce light indications in a plurality of free spectral paths. These light indications are introduced through slits to produce signals at spaced positions at the opposite peripheries of a linear detector array. The distances between correlated pairs of energized detectors at the opposite peripheries of the array indicate the relative value of the laser wavelength in the free spectral ranges. The laser light beam is also processed in a second optical path, simultaneously with the processing of the laser light beam in the first optical path, to produce light in a single path. The second optical path is dependent upon the wavelength of the laser light beam. The light produced in the second optical path may be introduced through another slit to energize centrally disposed detectors in the array. The particular detectors energized are dependent upon the wavelength of the laser light. The detectors in the linear array may be scanned to produce signals related in time to the disposition of the detectors energized in the array. A data processing system processes these signals and produces a signal to adjust the wavelength of the laser beam to a particular value. When the laser is pulsed, the system described above may operate in real time after each pulse to adjust the laser before the next pulse to produce light at the particular wavelength.

System for, and method of, regulating the wavelength of a light beam

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San Diego, CA, United States of America

Stuart L Anderson