John Michael Rauch

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.