Mr. Frank Flohrer Profile

Frank Flohrer

at j-fiber GmbH

SPIE Involvement:

Author

Publications (6)

Proceedings Article | 11 February 2011 Paper

Fibers and fiber-optic components for high-power fiber lasers

H. Zimer, M. Kozak, A. Liem, F. Flohrer, F. Doerfel, P. Riedel, S. Linke, R. Horley, F. Ghiringhelli, S. Desmoulins, M. Zervas, J. Kirchhof, S. Unger, S. Jetschke, T. Peschel, T. Schreiber

Proceedings Volume 7914, 791414 (2011) https://doi.org/10.1117/12.879622

KEYWORDS: Fiber lasers, Absorption, Optical fibers, Ytterbium, Phosphorus, Glasses, Refractive index, Aluminum, Cladding, Single mode fibers

Read Abstract +

Proceedings Article | 20 September 2004 Paper

High-power sources for EUV lithography: state of the art

Uwe Stamm, Juergen Kleinschmidt, Kai Gaebel, Henry Birner, Imtiaz Ahmad, Denis Bolshukhin, Jesko Brudermann, Tran Duc Chinh, Frank Flohrer, Sven Goetze, Guido Hergenhan, Diethard Kloepfel, Vladimir Korobochko, Bjoern Mader, Rainer Mueller, Jens Ringling, Guido Schriever, Christian Ziener

Proceedings Volume 5448, (2004) https://doi.org/10.1117/12.548385

KEYWORDS: Extreme ultraviolet, Plasma, Extreme ultraviolet lithography, Tin, Mirrors, Xenon, Solids, Optics manufacturing, High volume manufacturing, Reflectivity

Read Abstract +

The availability of extreme ultraviolet (EUV) light sources, measurement tools and integrated test systems is of major importance for the development of EUV lithography for use in high volume chip manufacturing which is expected to start in 2009. The estimates of cost of an EUV exposure tool in combination with sophisticated throughput models leads to a throughput of 120 wafers per hour necessary for economic use of EUV lithography. Concluding from that light sources are necessary which deliver an EUV output power of 115 W at 13.5 nm at the entrance of the illuminator system. The power requirement in combination with the required lifetimes of source components and collector optics make the source technology the most critical issue to be solved when developing EUV lithography. The present paper gives an update of the development status of EUV light sources at XTREME technologies, a joint venture of Lambda Physik AG, Goettingen, and Jenoptik LOS GmbH, Jena, Germany. Results on both laser produced plasma (LPP) and gas discharge produced plasma (GDPP), the two major technologies in EUV sources, are given. The LPP EUV sources use xenon-jet target systems and pulsed lasers with 500 W average power at up to 10 kHz developed at XTREME technologies. The maximum conversion efficiency from laser power into EUV in-band power is 1.0% into 2π solid angle. 2.0 W EUV radiation is generated at 13.5 nm in 2π sr solid angle. The small source volume of < 0.3 mm diameter will allow large collection angles of 5 sr. The intermediate focus power is estimated to 1 W. Collector mirror lifetime tests showed 5 million pulses lifetime without debris mitigation. With debris mitigation in place lifetimes of more than 1 billion pulses are estimated. For the next generation of higher power EUV LPP sources a laser driver has been tested at 1.3 kW average laser power. This will lead to 5 W EUV power in intermediate focus. The GDPP EUV sources use the Z-pinch principle with efficient sliding discharge pre-ionization. Prototype commercial gas discharge sources with an EUV power of 35W in 2π sr were already delivered for integration into EUV microsteppers. These sources are equipped with a debris-filter which results in an optics lifetime exceeding 100 million discharges at 1 kHz repetition frequency. The same lifetime was achieved for the components of the discharge system itself. The progress in the development of high-power discharge sources resulted in an EUV power of 150 W in continuous operation at 4.5 kHz repetition rate by implementation of porous metal cooling technology. The EUV plasma has a FWHM-diameter of 0.5 mm and a FWHM-length of 1.5 mm. The intermediate focus power is calculated to be in the range of 15 W - 20 W, depending somewhat on the transmission of the optical path to the intermediate focus and on the etendue specification. The typical fluctuations of the EUV energy are standard deviation σ<5% without any active stabilization. Discharge sources with Sn as emitter were investigated as more efficient alternative to Xenon. Estimates regarding Sn sources reveal the potential of achieving 65 W intermediate focus power by using developed porous metal cooling technology. Improvement of cooling could open the path to 115 W of power for high volume manufacturing using EUV lithography. However, Sn-sources are technologically risky und much less advanced than Xe sources, since fuel-handling and debris mitigation is much more challenging in comparison to Xe-sources. GDPP and LPP sources still compete for the technology of high volume manufacturing sources for EUV lithography. Optimization potential of the etendue of the optical system of EUV scanners will certainly influence any technology decision for HVM sources.

Proceedings Article | 20 May 2004 Paper

EUV source power and lifetime: the most critical issues for EUV lithography

Uwe Stamm, Juergen Kleinschmidt, Kai Gaebel, Henry Birner, Imtiaz Ahmad, Denis Bolshukhin, Jesko Brudermann, Tran Duc Chinh, Frank Flohrer, Sven Goetze, Guido Hergenhan, Diethard Kloepfel, Vladimir Korobotchko, Bjorn Mader, Rainer Mueller, Jens Ringling, Guido Schriever, Christian Ziener

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.535410

KEYWORDS: Extreme ultraviolet, Plasma, Extreme ultraviolet lithography, Tin, Mirrors, Xenon, High volume manufacturing, Metals, Reflectivity, EUV optics

Read Abstract +

Semiconductor chip manufacturers are expecting to use extreme ultraviolet (EUV) lithography for high volume manufacturing of DRAMs and ICs starting by the end of this decade. Among all the technologies and modules which have to be developed EUV sources at 13.5 nm are considered to be the most critical issue. Specifically the required output power of 115 W at the entrance of the illuminator system in combination with the required lifetimes of source components and collector optics make the source technology critical for EUV lithography. The present paper gives an update of the development status of EUV light sources at XTREME technologies, a joint venture of Lambda Physik AG, Goettingen, and Jenoptik LOS GmbH, Jena, Germany. Results on both laser produced plasma (LPP) and gas discharge produced plasma (GDPP), the two major technologies in EUV sources, are given. The LPP EUV sources use xenon-jet target systems and pulsed lasers with 500 W average power at up to 10 kHz developed at XTREME technologies. The maximum conversion efficiency from laser power into EUV in-band power is 1.0 % into 2p solid angle. 2.0 W EUV radiation is generated at 13.5 nm in 2p sr solid angle. The small source volume of < 0.3 mm diameter will allow large collection angles of 5 sr. The intermediate focus power is estimated to 1 W. Collector mirror lifetime tests showed 5 million pulses lifetime without debris mitigation. With debris mitigation in place lifetimes of more than 1 billion pulses are estimated. For the next generation of higher power EUV LPP sources a laser driver has been tested at 1.3 kW average laser power. This will lead to 5 W EUV power in intermediate focus. The GDPP EUV sources use the Z-pinch principle with efficient sliding discharge pre-ionization. Prototype commercial gas discharge sources with an EUV power of 35W in 2p sr were already delivered for integration into EUV microsteppers. These sources are equipped with a debris-filter which results in an optics lifetime exceeding 100 million discharges at 1 kHz repetition frequency. The same lifetime was achieved for the components of the discharge system itself. The progress in the development of high-power discharge sources resulted in an EUV power of 150 W in continuous operation at 4.5 kHz repetition rate by implementation of porous metal cooling technology. The EUV plasma has a FWHM-diameter of 0.5 mm and a FWHM-length of 1.5 mm. The intermediate focus power is calculated to be in the range of 15 W - 20 W, depending somewhat on the transmission of the optical path to the intermediate focus and on the etendue specification. The typical fluctuations of the EUV energy are standard deviation s<5% without any active stabilization. Discharge sources with Sn as emitter were investigated as more efficient alternative to Xenon. Estimates regarding Sn sources reveal the potential of achieving 65 W intermediate focus power by using developed porous metal cooling technology. Improvement of cooling could open the path to 115 W of power for high volume manufacturing using EUV lithography. However, Sn-sources are technologically risky und much less advanced than Xe sources, since fuel-handling and debris mitigation is much more challenging in comparison to Xe-sources. GDPP and LPP sources still compete for the technology of high volume manufacturing sources for EUV lithography. Optimization potential of the etendue of the optical system of EUV scanners will certainly influence any technology decision for HVM sources.

Proceedings Article | 16 June 2003 Paper

High-power EUV lithography sources based on gas discharges and laser-produced plasmas

Uwe Stamm, Imtiaz Ahmad, Istvan Balogh, H. Birner, D. Bolshukhin, J. Brudermann, S. Enke, Frank Flohrer, Kai Gäbel, S. Götze, G. Hergenhan, Jürgen Kleinschmidt, Diethard Klöpfel, Vladimir Korobotchko, Jens Ringling, Guido Schriever, C. Tran, C. Ziener

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.482676

KEYWORDS: Extreme ultraviolet, Plasmas, Solids, Xenon, Extreme ultraviolet lithography, Optical filters, Gas lasers, EUV optics, Lithography, Reflectivity

Read Abstract +

Semiconductor chip manufacturers are expecting to use extreme UV lithography for production in 2009. EUV tools require high power, brilliant light sources at 13.5 nm with collector optics producing 120 W average power at entrance of the illuminator system. Today the power and lifetime of the EUV light source are considered as the most critical issue for EUV lithography. The present paper gives an update of the development status of EUV light sources at XTREME technologies, a joint venture of Lambda Physik AG, Goettingen, and Jenoptik LOS GmbH, Jena, Germany. Results on both laser produced plasma (LPP) and gas discharge produced plasma (GDPP), the two major technologies in EUV sources, are given. The LPP EUV sources use xenon-jet target systems and pulsed lasers with 400 W average power at 10 kHz developed at XTREME technologies. The maximum conversion efficiency form laser power into EUV in-band power is 0.75% into 2π solid angle. With 300 W laser average power at 3300 Hz repetition rate up to 1.5 W EUV radiation is generated at 13.5 nm. After a collector of 5 sr this corresponds to 0.6 W in intermediate focus without spectral purity filter and 0.5 W in intermediate focus with spectral purity filter. The direct generation of the EUV emitting plasma from electrical discharges is much simpler than LPP because the electrical energy has not to be converted into laser radiation before plasma excitation. XTREME technologies' Xenon GDPP EUV sources use the Z-pinch principle with efficient sliding discharge pre-ionization. The plasma pinch size and the available emission angle have been matched to the etendue of the optical system of 2-3 mm2 sr, i.e. no additional etendue related loss reduces the usable EUV power from the source. In continuous operation at 1000 Hz the GDPP sources emit 50W into 2π solid angle are obtained from the Z-pinch sources. Spatial and temporal emission stability of the EUV sources is in the range of a few percent. Debris shields for EUV sources have been developed which give improvement of the collector optics lifetime by several orders of magnitude.

Proceedings Article | 1 July 2002 Paper

High-power EUV sources for lithography: a comparison of laser-produced plasma and gas-discharge-produced plasma

Uwe Stamm, Imtiaz Ahmad, Vladimir Borisov, Frank Flohrer, Kai Gaebel, S. Goetze, Alexander Ivanov, Oleg Khristoforov, Diethard Kloepfel, Peter Koehler, Juergen Kleinschmidt, Vladimir Korobotchko, Jens Ringling, Guido Schriever, Aleksandr Vinokhodov

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472283

KEYWORDS: Extreme ultraviolet, Plasma, Solids, Optical filters, Xenon, Calibration, Extreme ultraviolet lithography, Lithography, Liquids, Plasma generation

Read Abstract +

Next generation semiconductor chip manufacturing using extreme ultraviolet (EUV) lithography requires a brilliant radiation source with output power between 50 W and 120 W in intermediate focus. This is about five to ten times higher power than that of current DUV excimer lasers used in optical lithography. Lifetime and cost of ownership however, need to be comparable to today's technology. In the present paper experimental results of both laser produced plasma and gas discharge produced plasma EUV source development at XTREME technologies - the EUV joint venture of Lambda Physik AG, Goettingen, and Jenoptik LOS GmbH, Jena, Germany - are presented. Source characterization has been performed with calibrated metrology tools for measurement of energy, power, size, spectra and stability of the EUV emission. The laser plasma investigations are performed with a 1st experimental facility comprising a commercial 40 W Nd:YAG laser coupled to a liquid xenon-jet target system, which was developed by XTREME technologies. The EUV in-band power emitted from the 0.25 mm diameter plasma into 2p solid angle is 0.2 W, the conversion efficiency amounts 0.5 percent. Estimated EUV emission parameters using a 500 W laser for plasma generation to be installed in spring 2002 are discussed. The gas discharge EUV sources described here are based on efficient Xenon Z-pinches. In the 3rd prototype generation the plasma pinch size and the available emission angle have been matched to the etendue of the optical system of 2-3 mm2. The solid angle of emission from the pinch of 1.3 mm x 1.5 mm amounts 1.8 sr. The Z-pinch EUV source can be operated continuously at 1000 Hz with an in-band output power of 10 W in 1.8 sr. This corresponds to 4.5 W in intermediate focus, if no spectral purity filter is needed. The power emitted into a solid angle of 2p sr is 35 W. Emission energy stability ranges between 1 percent and 4 percent standard deviation. Spectral, temporal as well as spatial emission characteristics of the discharge source in dependence on the gas discharge geometry have been evaluated. The potentials as well as limits for power scaling of the two technological source concepts are discussed.

Proceedings Article | 6 May 2002 Paper

High-power-gas-discharge- and laser-plasma-based EUV sources

Frank Flohrer, Kai Gaebel, Diethard Kloepfel, Peter Koehler, Imtiaz Ahmad, S. Goetze, Juergen Kleinschmidt, Vladimir Korobotchko, Jens Ringling, Guido Schriever, Uwe Stamm

Proceedings Volume 4631, (2002) https://doi.org/10.1117/12.465786

KEYWORDS: Extreme ultraviolet, Plasmas, Xenon, Mirrors, High power lasers, Liquids, Solids, Calibration, Extreme ultraviolet lithography, Pulsed laser operation

Read Abstract +

Showing 5 of 6 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years