Patent US3464337A successfully refreshed from Google Patents.
Patent US6477193B2 successfully refreshed from Google Patents.
US6477193B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extreme repetition rate gas discharge laser with improved blower motor
Assignee: Cymer Inc
•
Filing: 2000-12-22
•
Granted: 2002-11-05
•
Expires: 2020-12-22
Abstract
Abstract A gas discharge laser capable of operating at pulse rates in the range of 4,000 Hz to 6,000 Hz at pulse energies in the range of 5 mJ to 10 mJ or greater. Important improvements over prior art designs include: (1) a squirrel cage type fan for producing gas velocities through the discharge region of more than 67 m/s and capable of continuous trouble-free operation for several months, (2) a liquid cooled drive motor having a low loss sealing member separating the motor rotor from the motor starter and protecting the motor from the laser gas and a breach detection device for detecting any breach of the sealing member, (3) a heat exchanger system capable of removing in excess of 16 kw of heat energy from the laser gas and (4) a pulse power system capable of providing precisely controlled electrical pulses to the electrodes needed to produce laser pulses at the desired pulse energies in the range of 5 mJ to 10 mJ or greater at pulse repetition rates in the range of 4,000 Hz to 6,000 Hz or greater.
Inventors
- 👤 I. Roger Oliver
- 👤 William N. Partlo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:17
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/22; H01S3/223; H01S3/225; G; G03; G03F; G03F7/00; G03F7/70; G03F7/70008; G03F7/70025; G03F7/70041; G03F7/70216; G03F7/70325; G03F7/70333; G03F7/70483; G03F7/7055; G03F7/70575; G03F7/708; G03F7/70908; G03F7/70933; H01S3/02; H01S3/03; H01S3/036; H01S3/038; H01S3/0385; H01S3/09; H01S3/097; H01S3/10; H01S3/102; H01S3/104; H03; H03K; H03K17/00; H03K17/51; H03K17/80; H03K3/00; H03K3/02; H03K3/53; H03K3/57; H01S3/04; H01S3/0404; H01S3/041; H01S3/09702; H01S3/0971; H01S3/0975; H01S3/105; H01S3/1055; H01S3/13; H01S3/131; H01S3/134; H01S3/2207
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
243 words
An extreme repetition rate gas discharge laser capable of operating at pulse repetition rates in the range of 4,000 to 6,000 pulses per second, said laser comprising: A) a laser chamber having two elongated electrodes, defining a discharge region and containing laser gas, B) a squirrel cage type tangential fan for circulating said laser gas producing sufficient gas velocities in said discharge region to clear from said discharge region, following each pulse, substantially all discharge produced ions prior to a next pulse when operating at a repetition rate in the range of 4,000 pulses per second or greater, C) a finned heat exchanger system capable of removing at least 16 kw of heat energy from said laser gas, D) a pulse power system configured to provide electrical pulses to said electrodes sufficient to produce laser pulses at rates of at least 4,000 pulses per second with precisely controlled pulse energies in the range of about 5 mJ to 10 mJ, and E) a laser beam measurement and control system capable of measuring pulse energy energy wavelength and bandwidth of substantially every pulse with feedback control of pulse energy and wavelength, and F) a liquid cooled motor, defining a rotor and a stator, driving said tangential fan, said motor comprising; 1) a pressure cup sealing member separating said stator from said rotor and protecting said stator from said laser gas and 2) a breach detection means for detecting a breach of said sealing member.
Claim 2
Dependent Claim
243 words
An extreme repetition rate gas discharge laser capable of operating at pulse repetition rates in the range of 4,000 to 6,000 pulses per second, said laser comprising: A) a laser chamber having two elongated electrodes, defining a discharge region and containing laser gas, B) a squirrel cage type tangential fan for circulating said laser gas producing sufficient gas velocities in said discharge region to clear from said discharge region, following each pulse, substantially all discharge produced ions prior to a next pulse when operating at a repetition rate in the range of 4,000 pulses per second or greater, C) a finned heat exchanger system capable of removing at least 16 kw of heat energy from said laser gas, D) a pulse power system configured to provide electrical pulses to said electrodes sufficient to produce laser pulses at rates of at least 4,000 pulses per second with precisely controlled pulse energies in the range of about 5 mJ to 10 mJ, and E) a laser beam measurement and control system capable of measuring pulse energy energy wavelength and bandwidth of substantially every pulse with feedback control of pulse energy and wavelength, and F) a liquid cooled motor, defining a rotor and a stator, driving said tangential fan, said motor comprising; 1) a pressure cup sealing member separating said stator from said rotor and protecting said stator from said laser gas and 2) a breach detection means for detecting a breach of said sealing member.
Claim 3
Dependent Claim
16 words
A laser as in claim 1 wherein said liquid cooled motor is a water cooled motor.
Claim 4
Dependent Claim
23 words
A laser as in claim 2 wherein said pressure cup sealing member is comprised of a metal no thicker than about 0.005 inch.
Claim 5
Dependent Claim
16 words
A laser as in claim 2 wherein said pressure cup is comprised of a non-conductive material.
Claim 6
Dependent Claim
19 words
A laser as in claim 4 wherein said bearings are comprised of a roller bearing and a ball bearing.
Claim 7
Dependent Claim
22 words
A laser as in claim 4 wherein said ceramic bearings are two ball bearings defining a drive bearing and an idle bearing.
Claim 8
Dependent Claim
16 words
A laser as in claim 2 wherin said pressure cup is comprised of a ceramic material.
Claim 9
Dependent Claim
13 words
A laser as in claim 7 wherein said ceramic material is aluminium oxide.
Claim 10
Dependent Claim
45 words
A laser as in claim 7 wherein preload applied to said ball bearing by a drive motor having a stator and a rotor with its rotor defining an axial magnetic center, said center being slightly off center of a magnetic field produced by the stator.
Claim 11
Dependent Claim
20 words
A laser as in claim 2 wherein said water cooled motor comprises a helical coil water path surrounding said stater.
Claim 12
Dependent Claim
29 words
A laser as in claim 2 and wherein said chamber also comprises a vane structure upstream of said discharge region for normalizing gas velocity upstream of said discharge region.
Claim 13
Dependent Claim
14 words
A laser as in claim 1 wherein said detection means is a pressure detector.
Claim 14
Dependent Claim
26 words
A laser as in claim 12 wherein said pressure detector is configured to de-energize said motor in the event of a rupture of said pressure cup.
Claim 15
Dependent Claim
16 words
A laser as in claim 13 wherein said magnetic force is produced by a drive motor.
Claim 16
Dependent Claim
31 words
A laser as in claim 12 wherein preload is applied to both of said bearings with a spring and additional preload is applied to said drive bearing by a magnetic force.
Claim 17
Dependent Claim
15 words
A laser as in claim 1 wherein said finned heat exchanger system is water cooled.
Claim 18
Dependent Claim
20 words
A laser as in claim 16 wherein said heat exchanger system comprises at least four separate water cooled heat exchangers.
Claim 19
Dependent Claim
22 words
A laser as in claim 17 wherein each of said four heat exchangers comprise a tubular water flow passage containing a turbulator.
Claim 20
Dependent Claim
32 words
A laser as in claim 16 wherein heat exchanger system comprises at least one heat exchanger having a tubular water flow passage wherein at least one turbulator is located in said path.
Claim 21
Dependent Claim
17 words
A laser as in claim 1 wherein said pulse power power system comprise water cooled electrical components.
Claim 22
Dependent Claim
27 words
A laser as in claim 20 wherein at least one of said water cooled components is a component operated at high voltages in excess of 12,000 volts.
Claim 23
Dependent Claim
22 words
A laser as in claim 21 wherein said high voltage is isolated from ground using an inductor through which cooling water flows.
Claim 24
Dependent Claim
26 words
A laser as in claim 1 wherein said pulse power system comprises a resonant charging system to charge a charging capacitor to a precisely controlled voltage.
Claim 25
Dependent Claim
15 words
A laser as in claim 23 wherein said resonance charging system comprises a De-Qing circuit.
Claim 26
Dependent Claim
15 words
A laser as in claim 23 wherein said resonance charging system comprises a bleed circuit.
Claim 27
Dependent Claim
19 words
A laser as in claim 23 wherein said resonant charging system comprises a De-Qing circuit and a bleed circuit.
Claim 28
Dependent Claim
25 words
A laser as in claim 1 wherein said pulse power system comprises a charging system comprised of at least three power supplies arranged in parallel.
Claim 29
Dependent Claim
16 words
A laser as in claim 1 wherein said fan comprises a shaft supported by ceramic bearings.
References Cited (Backward Citations)
US3849670A
Cited
US4549091A
Cited
US4803378A
Cited
US4697270A
Cited
US4798467A
Cited
US4940331A
Cited
US5177754A
Cited
US5315611A
Cited
US4817101A
Cited
US5023884A
Cited
US5138622A
Cited
US5128601A
Cited
US5025445A
Cited
US5359279A
Cited
US5095492A
Cited
US5124629A
Cited
US5691989A
Cited
US5142166A
Cited
US5514918A
Cited
US5371587A
Cited
US5524144A
Cited
US5319665A
Cited
US5309462A
Cited
US5420877A
Cited
US5450207A
Cited
US5313481A
Cited
US5448580A
Cited
US5754571A
Cited
US5729562A
Cited
JPH09101587A
Cited
US5706301A
Cited
US5982800A
Cited
US6005879A
Cited
US6128323A
Cited
US5848089A
Cited
US5852621A
Cited
US6078599A
Cited
US5870420A
Cited
US5936988A
Cited
US6151346A
Cited
US6240112B1
Cited
US20020044597A1
Cited
US5978405A
Cited
US5991324A
Cited
US6026103A
Cited
US20020021728A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-11-04 | 2006-05-06 | 2006-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-11-04 | 2010-05-06 | 2010-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-11-04 | 2014-05-06 | 2014-11-05 | $7700.00 | Window Closed / Lapsed |