Xiaojiang Jason Pan

US Patent:

6359922, Mar 19, 2002

Filed:

Oct 20, 1999

Appl. No.:

09/421701

Inventors:

William N. Partlo - Poway CA
Xiaojiang Pan - San Diego CA
Eckehard D. Onkels - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 322

US Classification:

372 58, 372 57

Abstract:

A single chamber gas discharge laser system having a pulse power source for producing electrical discharges at the rate of at least 1000 pulses per second. The discharge along with laser optics create two short lived gain media, one for producing a seed beam and the other for amplifying the seed beam. Laser gas circulation around a chamber circulation path is provided and the electrodes and discharges are arranged so that debris from one of the gain media is not circulated to the other gain media during discharges until the debris has made a loop around at least 90% of the chamber circulation path.

US Patent:

6466601, Oct 15, 2002

Filed:

Apr 13, 2001

Appl. No.:

09/834840

Inventors:

Xiaojiang J. Pan - San Diego CA
Vladimir Kulgeyko - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 303

US Classification:

372 61, 372 57, 372107

Abstract:

A gas discharge modular laser with beam train isolation between laser chamber module and front and rear optics which define the laser resonant cavity. Beam train isolation units isolates the beam train from atmospheric air while permitting quick and easy removal of the laser chamber without disturbing the optics of the resonant cavity. In preferred embodiments, metal bellows units are bolted at only side so that the chamber module can be removed and replaced without unbolting the bellows unit.

US Patent:

6567450, May 20, 2003

Filed:

Aug 29, 2001

Appl. No.:

09/943343

Inventors:

David W. Myers - Poway CA
Herve A. Besaucele - San Diego CA
Alexander I. Ershov - San Diego CA
William N. Partlo - Poway CA
Richard L. Sandstrom - Encinitas CA
Palash P. Das - Vista CA
Stuart L. Anderson - San Diego CA
Igor V. Fomenkov - San Diego CA
Richard C. Ujazdowski - San Diego CA
Xiaojiang J. Pan - San Diego CA
Eckehard D. Onkels - San Diego CA
Richard M. Ness - San Diego CA
Daniel J. W. Brown - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 322

US Classification:

372 55, 372 57, 372 58, 372 59, 372 25

Abstract:

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.

US Patent:

6511703, Jan 28, 2003

Filed:

Jul 20, 2001

Appl. No.:

09/910362

Inventors:

Xiaojiang J. Pan - San Diego CA
Richard G. Morton - San Diego CA
Alexander I. Ershov - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

C23C 1424

US Classification:

427166, 427250, 42725515, 4272557, 427294, 20419211, 20419226, 20419227

Abstract:

An overcoat protected diffraction grating. A replica grating having a thin aluminum reflective grating surface is produced by replication of a master grating or a submaster grating. The thin aluminum reflective surface may be cracked or have relatively thick grain boundaries containing oxides and hydroxides of aluminum and typically is also naturally coated with an aluminum oxide film. The grating is subsequently overcoated in a vacuum chamber with one or two thin, pure, dense aluminum overcoat layers and then also in the vacuum the aluminum overcoat layer or layers are coated with one or more thin protective layers of a material transparent to ultraviolet radiation. In preferred embodiments this protective layer is a single layer of MgF , SiO or Al O. In other preferred embodiments the layer is a layer of MgF or SiO covered with a layer of Al O and in a third preferred embodiment the protective layer is made up of four alternating layers of MgF and Al O or four alternating layers of SiO and Al O. Preferably, the thickness of the transparent protective layers are chosen to produce a phase shift at the proposed operating wavelengths of an integral number of 2.

US Patent:

6529321, Mar 4, 2003

Filed:

Dec 7, 2000

Appl. No.:

09/731938

Inventors:

Xiaojiang J. Pan - San Diego CA
Richard G. Morton - San Diego CA
Alexander I. Ershov - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

G02B 508

US Classification:

359360, 359571, 359572, 359576

Abstract:

An overcoat protected diffraction grating. A replica grating having a thin aluminum reflective grating surface is produced by replication of a master grating or a submaster grating. The thin aluminum reflective surface may be cracked or have relatively thick grain boundaries containing oxides and hydroxides of aluminum and typically is also naturally coated with an aluminum oxide film. The grating is subsequently recoated in a vacuum chamber with a thin, pure, dense aluminum overcoat and then also in the vacuum the aluminum overcoat is coated with a thin film of MgF. The grating is especially suited for use for wavelength selection in an ArF laser operating producing an ultraviolet laser beam at a wavelength of about 193 nm. The oxygen free aluminum overcoat prevents the ultraviolet light from causing damage by stimulating chemical reactions in grating materials under the aluminum grating surface or in the aluminum oxide film. The MgF additionally prevents oxidation on the surface, of the aluminum overcoat.

US Patent:

6539042, Mar 25, 2003

Filed:

Jan 29, 2001

Appl. No.:

09/771789

Inventors:

Shahryar Rokni - Carlsbad CA
Xiaojiang J. Pan - San Diego CA
Eckehard D. Onkels - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 322

US Classification:

372 59, 372 57, 372 58, 372 60

Abstract:

The present invention provides an ultra pure purge system for discharge lasers. The LNP, the output coupler, the wavemeter and selected high voltage components are contained in sealed chambers each having a purge inlet port and a purge outlet port. Purge gas such as N is filtered and directed to each of the inlet ports. Gas exiting the outlet ports may be directed to flow monitors having alarms so that any loss of purge will be immediately detected. Purge gas may be exhausted or recirculated.

US Patent:

6693939, Feb 17, 2004

Filed:

May 7, 2002

Appl. No.:

10/141216

Inventors:

Brian Klene - La Jolla CA
Palash P. Das - Vista CA
Steve Grove - Poway CA
Alexander Ershov - San Diego CA
Scot Smith - San Diego CA
Xiaojiang Pan - San Diego CA
Richard L. Sandstrom - Encinitas CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 322

US Classification:

372 58

Abstract:

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 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.

US Patent:

6757316, Jun 29, 2004

Filed:

May 11, 2001

Appl. No.:

09/854097

Inventors:

Peter C. Newman - San Diego CA
Thomas P. Duffey - San Diego CA
William N. Partlo - Poway CA
Richard L. Sandstrom - Encinitas CA
Paul C. Melcher - El Cajon CA
David M. Johns - Lakeside CA
Robert B. Saethre - San Diego CA
Vladimir B. Fleurov - Escondido CA
Richard M. Ness - San Diego CA
Curtis L. Rettig - Vista CA
Robert A. Shannon - Ramona CA
Richard C. Ujazdowski - San Diego CA
Shahryar Rokni - Carlsbad CA
Xiaojiang J. Pan - San Diego CA
Vladimir Kulgeyko - San Diego CA
Scott T. Smith - San Diego CA
Stuart L. Anderson - San Diego CA
John M. Algots - San Diego CA
Ronald L. Spangler - Arlington MA
Igor V. Fomenkov - San Diego CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 322

US Classification:

372 57, 372 25, 372 3802, 372 3804, 372 3807, 372 58, 372 59

Abstract:

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.