Cymer, Inc.

Robert A Shannon

Richard C Ujazdowski

Thomas Hofmann

Igor Vladimirovich Fomenkov

Tom A Watson

James K Howey

William N Partlo

Richard L Sandstrom

Richard M Ness

R Kyle Webb

Paul C Melcher

Curtis L Rettig

Richard G Morton

Thomas Patrick Duffey

John Martin Algots

Scott T Smith

Stuart L Anderson

Vladimir B Fleurov

Ronald L Spangler

Alex P Ivaschenko

Shahryar Rokni

Robert B Saethre

David M Johns

Alexander Igorevich Ershov

Peter Clarke Newman

Xiaojiang Jason Pan

Steven Merrill Harrington

Eckehard D Onkels

Donald G Larson

Thomas D Steiger

Toshihiko Ishihara

Paul S Thompson

I Roger Oliver

Raymond F Cybulski

Gamaralalage G Padmabandu

Jean-Marc Hueber

Paolo Zambon

Frederick A Palenschat

James H Azzola

Dmitry Berger

Michael C Cates

Vladimir A Kulgeyko

Mark Branham

Clay C Titus

Dmitri V Gaidarenko

Christian J Wittak

Ross H Winnick

Carl E Tedesco, Ii

Sunjay Phatak

Michael Du'Lyea

Jerome A Emilo

B Fleurov Vladimir

The present invention provides gas discharge laser systems capable of reliable long-term operation in a production line capacity at repetition rates in the range of 6,000 to 10,0000 pulses power second. Preferred embodiments are configured as KrF, ArF and Flasers used for light sources for integrated circuit lithography. Improvements include a modified high voltage power supply capable for charging an initial capacitor of a magnetic compression pulse power system to precise target voltages 6,000 to 10,0000 times per second and a feedback control for monitoring pulse energy and determining the target voltages on a pulse-by-pulse basis. Several techniques are disclosed for removing discharge created debris from the discharge region between the laser electrodes during the intervals between discharges. In one embodiment the width of the discharge region is reduced from about 3 mm to about 1 mm so that a gas circulation system designed for 4,000 Hz operation could be utilized for 10,000 Hz operation. In other embodiments the gas flow between the electrodes is increased sufficiently to permit 10,000 Hz operation with a discharge region width of 3 mm. To provide these substantial increased gas flow rates, Applicants have disclosed preferred embodiments utilize tangential forms of the prior art but with improved and more powerful motors and novel bearing designs. New bearing designs include both ceramic bearings and magnetic bearings. In other embodiments, some or all of the gas circulation power is provided with a blower located outside the laser chamber. The outside blower can be located in the laser cabinet or in separate location.

Six to ten KHz, or greater 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

A gas discharge laser having a laser chamber with two elongated erodable electrode elements, each having an erodable section and an electrode with support configured to minimize discharge region laser gas turbulence and with the electrode elements being configured to permit gradual erosion over more than 8 billion pulses without causing substantial changes in the shape of electrical discharges between the electrode elements. A pulse power system provides electrical pulses of at least 2J at rates of at least 2 KHz. A blower circulates laser gas between the electrodes at speeds of at least 2 m/s and a heat exchanger is provided to remove heat produced by the blower and the discharges.

Gas discharge laser long life electrodes

A tangential fan and cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential position of blade members can shift monotonically or reversibly between ends. Blade members are stiffened by optimally selecting the number and placement of hub members to control the natural vibration frequency of the fan. Methods of forming tangential fans include casting, and machining from a solid block. Monolithic structures can be joined, typically by electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Tangential fans produced have mechanical rigidity, accurate tolerances, and low contaminant concentrations. Blade members can be formed into air foil shapes.

Tangential fan with cutoff assembly and vibration control for electric

A tangential fan for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end. The number of blade members can be constant or variable between ends. The circumferential position of blade members can shift monotonically or reversibly between ends. Blade members are stiffened by one or more transverse annular hub members. A method of forming a tangential fan involves forming monolithic structures by casting or by machining from a solid block. Two or more monolithic structures can be joined together, typically by electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Tangential fans produced have mechanical rigidity, accurate tolerances, and low contaminant concentrations. Methods provided by the invention facilitate forming of blade members into an air foil shape. Finishing processes typically include post-machining, electropolishing, and electroless nickel coating.

Tangential fan for excimer laser

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

A tangential fan with cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential positions of blade members can shift monotonically or reversibly between ends. Blade members can be formed into air foil shapes and are stiffened by one or more transverse annular hub members. Processes for making tangential fans include soldering, casting, and machining from a solid block. Monolithic structures can be joined, typically by soldering or electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Soldering produces substantially silicon-free assemblies. Tangential fans produced in accordance with the invention have improved mechanical rigidity, accurate tolerances, and low contaminant concentrations.

Soldered fan assembly for electric discharge laser

Growing community of inventors

El Cajon, CA, United States of America

Robert A Shannon