Richard E Sandstrom

US Patent:

6586757, Jul 1, 2003

Filed:

Jun 6, 2001

Appl. No.:

09/875719

Inventors:

Stephan T. Melnychuk - Carlsbad CA
William N. Partlo - Poway CA
Igor V. Fomenkov - San Diego CA
Richard M. Ness - San Diego CA
Daniel L. Birx late of - Potomac MD
Richard L. Sandstrom - Encinitas CA
John E. Rauch - Poway CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01J 3520

US Classification:

250504R, 2504931, 378119

Abstract:

A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. The chamber contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at repetition rates of 1000 Hz or greater and at voltages high enough to create electrical discharges between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the source or active gas. A fourth generation unit is described which produces 20 mJ, 13. 5 nm pulses into 2 steradians at repetition rates of 2000 Hz with xenon as the active gas. This unit includes a pulse power system having a resonant charger charging a charging capacitor bank, and a magnetic compression circuit comprising a pulse transformer for generating the high voltage electrical pulses at repetition rates of 2000 Hz or greater. Gas flows in the vacuum chamber are controlled to assure desired concentration of active gas in the discharge region and to minimize active gas concentration in the beam path downstream of the pinch region.

US Patent:

6644324, Nov 11, 2003

Filed:

Mar 6, 2000

Appl. No.:

09/518970

Inventors:

Tom A. Watson - Carlsbad CA
Richard L. Sandstrom - Encinitas CA
Richard G. Morton - San Diego CA
Robert E. Weeks - San Diego CA
John P. Quitter - San Diego CA
Mark R. Lewis - Oceanside CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

B08B 704

US Classification:

134 11, 134 2218, 134 30

Abstract:

Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than conventional thermal cleaning and passivation processes.

US Patent:

6798812, Sep 28, 2004

Filed:

Sep 13, 2002

Appl. No.:

10/243102

Inventors:

German E. Rylov - Murrieta CA
Thomas Hofmann - San Diego CA
Richard L. Sandstrom - Encinitas CA

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 3223

US Classification:

372 55, 372 57, 372 58, 372 59, 372 60, 372 61

Abstract:

The present invention provides 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 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts 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 parameters chamber can be controlled separately permitting optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment is a F laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In this preferred embodiment, both of the chambers and the laser optics are mounted on a vertical optical table within a laser enclosure. 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.

US Patent:

6914919, Jul 5, 2005

Filed:

Jun 28, 2002

Appl. No.:

10/187336

Inventors:

Tom A. Watson - Carlsbad CA, US
Richard C. Ujazdowski - San Diego CA, US
Alex P. Ivaschenko - San Diego CA, US
Richard L. Sandstrom - Encinitas CA, US
Robert A. Shannon - Ramona CA, US
R. Kyle Webb - Escondido CA, US
Frederick A. Palenschat - Lemon Grove CA, US
Thomas Hofmann - San Diego CA, US
Curtis L. Rettig - Vista CA, US
Richard M. Ness - San Diego CA, US
Paul C. Melcher - El Cajon CA, US
Alexander I. Ershov - San Diego CA, US

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S003/10
H01S003/22

US Classification:

372 25, 372 55, 372 57, 372 58

Abstract:

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.

US Patent:

6914927, Jul 5, 2005

Filed:

Aug 26, 2003

Appl. No.:

10/649186

Inventors:

Tom A. Watson - Carlsbad CA, US
Richard L. Sandstrom - Encinitas CA, US
Richard G. Morton - San Diego CA, US
Robert E. Weeks - San Diego CA, US
John P. Quitter - Escondido CA, US
Mark R. Lewis - Oceanside CA, US

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S003/22
H01S003/03
H01S003/091
H01S003/09

US Classification:

372 58, 372 55, 372 57, 372 59, 372 61, 372 76, 372 82, 372 90

Abstract:

Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than conventional thermal cleaning and passivation processes.

US Patent:

8265109, Sep 11, 2012

Filed:

Apr 21, 2009

Appl. No.:

12/386771

Inventors:

Palash P. Das - Oceanside CA, US
Thomas Hofmann - San Diego CA, US
Jesse D. Davis - Coronado CA, US
Richard L. Sandstrom - Encinitas CA, US

Assignee:

Cymer, Inc. - San Diego CA

International Classification:

H01S 3/10

US Classification:

372 25

Abstract:

A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.

US Patent:

20120298838, Nov 29, 2012

Filed:

Aug 9, 2012

Appl. No.:

13/571129

Inventors:

Palash P. Das - Oceanside CA, US
Thomas Hofmann - San Diego CA, US
Jesse D. Davis - Coronado CA, US
Richard L. Sandstrom - Encinitas CA, US

Assignee:

CYMER, INC. - San Diego CA

International Classification:

G01J 1/16

US Classification:

2502011

Abstract:

A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.