Cymer, Inc.

Intralase Corporation

USA As Represented by Secretary of the Navy

R Kyle Webb

Alexander Igorevich Ershov

Richard L Sandstrom

Richard C Ujazdowski

Tom A Watson

Thomas Hofmann

Palash P Das

Tibor Juhasz

Carlos German Suarez

Robert A Shannon

William N Partlo

Richard G Morton

Richard M Ness

Oleh V Khodykin

David J Warkentin

Herve A Besaucele

James K Howey

Peter Goldstein

Roy S Luoma

Holger K Glatzel

Leonard Lublin

Gregory Francis

Scott A DeLong

Igor Vladimirovich Fomenkov

Christopher Horvath

Marco Giovanardi

Alexander Bykanov

Ronald Michael Kurtz

Peter Clarke Newman

Thomas Patrick Duffey

Xiaojiang Jason Pan

John Martin Algots

Mark Wesley Ross

Thomas A Yager

Walter Dale Gillespie

Paul C Melcher

John T Melchior

Robert G Ozarski

Vladimir B Fleurov

Daniel Anthony Rothweil

David Wayne Myers

Paul S Thompson

Michael F Brownell

Curtis L Rettig

Gamaralalage G Padmabandu

Jerzy R Hoffman

Ronald L Spangler

Rodney D Simmons

Eric Alan Hillenbrand

Alex P Ivaschenko

Scot T Smith

Alexei Lukashev

Shahryar Rokni

Paolo Zambon

William N Partio

John Viatella

Frederick A Palenschat

Brian C Klene

Laszlo Nagy

Gordon Scott Scholler

Khurshid Ahmed

Huckleberry B Dorn

Elizabeth Marsh

Plash P Das

Kyle P Erlandsen

John W Nelson

Jeremy Tyler

John Walker

Matthew Ball

A laser produced plasma ('LPP') extreme ultraviolet ('EUV') light source and method of operating same is disclosed which may comprise an EUV plasma production chamber having a chamber wall; a drive laser entrance window in the chamber wall; a drive laser entrance enclosure intermediate the entrance window and a plasma initiation site within the chamber and comprising an entrance enclosure distal end opening; at least one aperture plate intermediate the distal opening and the entrance window comprising at least one drive laser passage aperture. The at least one aperture plate may comprise at least two aperture plates comprising a first aperture plate and a second aperture plate defining an aperture plate interim space. The at least one drive laser aperture passage may comprise at least two drive laser aperture passages. The laser passage aperture may define an opening large enough to let the drive laser beam pass without attenuation and small enough to substantially reduce debris passing through the laser passage aperture in the direction of the entrance window.

LPP EUV drive laser input system

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source with a beam delivery to a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. Preferred embodiments include equipment for beam attenuation, equipment for automatic feedback beam alignment and equipment for accurate optics module positioning at installation and during maintenance. In preferred embodiments, the production line machine is a lithography machine and 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. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout the operating life of the lithography system, despite substantial degradation of optical components.

Lithography laser with beam delivery and beam pointing control

A beam delivery unit and method of delivering a laser beam from a laser light source for excimer or molecular fluorine gas discharge laser systems in the DUV and smaller wavelengths is disclosed, which may comprise: a beam delivery enclosure defining an output laser light pulse beam delivery pat from an output of a gas discharge laser to an input of a working apparatus employing the light contained in the output laser light pulse beam; a purge mechanism operatively connected to the beam delivery enclosure; an in-situ beam parameter monitor and adjustment mechanism within the enclosure, comprising a retractable bean redirecting optic; a beam analysis mechanism external to the enclosure; and, a retraction mechanism within the enclosure and operable from outside the enclosure and operative to move the retractable beam redirecting optic from a retracted position out of the beam path to an operative position in the beam path. The BDU may also include a beam attenuator unit contained within the enclosure adjustably mounted within the enclosure for positioning within the beam delivery pat. The BDU may have at least two enclosure isolation mechanisms comprising a first enclosure isolation mechanism on a first side of the enclosure from the at least one optic module and a second enclosure isolation mechanism on a second side of the enclosure from the at least one optic module, each respective enclosure isolation mechanism comprising a flapper valve having a metal to metal seating mechanism and a locking pin assembly. A precision offset ratchet driver operative to manipulate actuator mechanisms in difficult to reach locations may be provided. An external kinematic alignment tool may be provided. A method of contamination control for a BDU is disclosed comprising selection of allowable materials and fabrication processes.

Gas discharge laser light source beam delivery unit

An DPP EUV source is disclosed which may comprise a debris mitigation apparatus employing a metal halogen gas producing a metal halide from debris exiting the plasma. The EUV source may have a debris shield that may comprise a plurality of curvilinear shield members having inner and outer surfaces connected by light passages aligned to a focal point, which shield members may be alternated with open spaces between them and may have surfaces that form a circle in one axis of rotation and an ellipse in another. The electrodes may be supplied with a discharge pulse shaped to produce a modest current during the axial run out phase of the discharge and a peak occurring during the radial compression phase of the discharge. The light source may comprise a turbomolecular pump having an inlet connected to the generation chamber and operable to preferentially pump more of the source gas than the buffer gas from the chamber. The source may comprise a tuned electrically conductive electrode comprising: a differentially doped ceramic material doped in a first region to at least select electrical conductivity and in a second region at least to select thermal conductivity. The first region may be at or near the outer surface of the electrode structure and the ceramic material may be SiC or alumina and the dopant is BN or a metal oxide, including SiO or TiO. The source may comprise a moveable electrode assembly mount operative to move the electrode assembly mount from a replacement position to an operating position, with the moveable mount on a bellows. The source may have a temperature control mechanism operatively connected to the collector and operative to regulate the temperature of the respective shell members to maintain a temperature related geometry optimizing the glancing angle of incidence reflections from the respective shell members, or a mechanical positioner to position the shell members. The shells may be biased with a voltage. The debris shield may be fabricated using off focus laser radiation. The anode may be cooled with a hollow interior defining two coolant passages or porous metal defining the passages. The debris shield may be formed of pluralities of large, intermediate and small fins attached either to a mounting ring or hub or to each other with interlocking tabs that provide uniform separation and strengthening and do not block any significant amount of light.

Discharge produced plasma EUV light source

A closed-loop focusing system and method positions a focusing assembly to a desired positioned. A feedback positioning device, such as a linear encoder, provides an actual or 'read' value for the linear movement of the focusing assembly. The desired position is compared to the actual position of the focusing assembly. If the two values are outside of a predetermined tolerance or valid range, then an audible or visual warning will be given. When a laser source is utilized with the focusing system, laser operation will be prevented if the two values are outside of an acceptable range. However, if the difference between the desired position and the actual position are within an acceptable range, the focusing assembly is repositioned to allow real-time systematic correction of the position of the focusing assembly.

Closed-loop focal positioning system and method

A method for applanating an anterior surface of a cornea and coupling the eye to a surgical laser is disclosed. A interface is provided which has a central orifice and top and bottom surfaces. A suction ring is removably coupled to the bottom surface of the interface. The interface is positioned over an operative area of an eye, such that the suction ring comes into proximate contact with the surface of the eye. A suction is applied to the suction ring to stabilize the position of the interface relative to the operative area of the eye. An applanation lens is positioned in proximate contact with the operative area of the eye. Finally, the applanation lens is coupled to the interface to stabilize the position of the lens relative to the operative area of the eye.

Ocular fixation and stabilization device for ophthalmic surgical applications

A calibration method for radiometric imaging systems that relies on an absolute measurement of scene radiance (thereby requiring a baseline measurement of zero radiance), and a shutter assembly for taking the baseline measurement of zero radiance which is operable under cryogenic temperatures as low as 80.5K (&#x2212;192.65&#xb0; C.) in vacuums measuring &#x3c;10torr (mm Hg). The shutter assembly generally includes an actuator and a shutter mechanism. The actuator is preferably a miniature solenoid assembly capable of operation in extreme environments (e.g. vacuums of &#x3c;10torr, temperatures below 90K). The shutter mechanism preferably includes a single shutter blade and is also capable of operation when subjected to extreme environments. The method of using the shutter assembly provides a zero radiance reference measurement for an infrared imaging system, thereby providing a basis upon which absolute scene radiance may be determined.

Miniature cryogenic shutter assembly

A method and apparatus for laser light pulse stretching is disclosed which may comprise a beam splitter in the path of a laser output light pulse beam; selected to pass a first percent of the energy of a first input pulse of the laser output light pulse beam along a laser output light pulse beam output path as a first output pulse and to reflect a second percent of the energy of the laser output light pulse beam into a first delayed beam; an optical delay path receiving the first delayed beam and returning the first delayed beam to the beam splitter in an orientation such that a third percent of the first delayed beam is reflected into the output path as a second output pulse and a fourth percent is passed into the optical delay path as a second delayed beam; the optical delay path receiving the second delayed beam and returning the second delayed beam to the beam splitter in an orientation such that the third percent of the second delayed beam is reflected into the output path as a third output pulse and the fourth percent of the second delayed beam is passed into the optical delay path as a third delayed beam; the optical delay path receiving the third delayed beam and returning the third delayed beam to the beam splitter in an orientation such that the third percent of the third delayed beam is reflected into the output path as a fourth output pulse; the first input pulse being a first pulse in a plurality of pulses output from a prior pulse stretcher, each of a plurality of succeeding input pulses comprising the output of the prior pulse stretcher resulting from the stretching of a narrow band laser light output pulse, forming successive first, second, third and fourth output pulses, the combination of which forms a pulse stretcher having an output with TIS of at least 200 ns. The optical delay path may be formed of a plurality of at least eight reflecting mirrors and contained in an elongated enclosure having first and second end plates mounting a first group of at least four of the at least eight reflecting mirrors mounted on the first mounting surface symmetrically about a center axis of the optical delay path and a second group of at least four of the at least eight reflecting mirrors mounted on the second mounting surface symmetrically about the center axis. The mirrors may be staggered in a predefined pattern, e.g., a circular pattern. The delay path may lie in a plurality of planes. The apparatus may be part of a laser system, part of a beam delivery system or an interface between the two.

Long delay and high TIS pulse stretcher

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 long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaFoptics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75&#xd7;10Watts/cmand with peak intensity or greater 3.5&#xd7;10Watts/cmfor many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities. Techniques and components are disclosed for minimizing the potential for optical damage and for reducing the pulse energy density to less than 100&#xd7;10J/cm. Important improvements described in this specification have been grouped into the following subject matter categories: (1) Solution to CaFsurface damage discovered by Applicants, (2) description of a high power ArF MOPA laser system, (3) description of beam delivery units, (4) polarization considerations (5) a high speed water-cooled auto shutter energy detector module and (6) other improvements.

High power deep ultraviolet laser with long life optics

An improved applanation lens and method for use in an interface between a patient's eye and a surgical laser system does not discolor or lose light transmittance when subjected to gamma radiation. The improved applanation lens has an applanation surface configured to contact the eye upon application of a pressure. The lens is formed of high purity silicon dioxide (SiO) with purity great enough to resist discoloration upon prolonged irradiation by high-energy radiation such as UV, x-rays, gamma rays or neutrons, and is preferably a fused silica.

Applanation lens and method for ophthalmic surgical applications

A closed-loop focusing system and method positions a focusing assembly to a desired positioned. A feedback positioning device, such as a linear encoder, provides an actual or &ldquo;read&rdquo; value for the linear movement of the focusing assembly. The desired position is compared to the actual position of the focusing assembly. If the two values are outside of a predetermined tolerance or valid range, then an audible or visual warning will be given. Furthermore, when a laser source is utilized with the focusing system, then laser operation will be prevented where the two values are outside of tolerance.

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and 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. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout the operating life of the lithography system, despite substantial degradation of optical components.

Applanation lens cone for ophthalmic laser surgery

Suction ring for ophthalmic laser surgery

Growing community of inventors

Escondido, CA, United States of America

R Kyle Webb