High Power Gas Discharge and Laser Produced Plasma Sources for EUV Lithography

Transcription

1 High Power Gas Discharge and Laser Produced Plasma Sources for EUV Lithography U. Stamm, I. Ahmad, I. Balogh, H. Birner, D. Bolshukhin, J. Brudermann, S. Enke, F. Flohrer, K. Gäbel, S. Götze, G. Hergenhan, J. Kleinschmidt, D. Klöpfel, P. Köhler, V. Korobochko, B. Mader, R. Müller, J. Ringling, G. Schriever, C. D. Tran, C. Ziener XTREME technologies, Göttingen and Jena, Germany 2 nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium funded by BMBF contract # 13N8131 and part of the MEDEA+ project T405 EUV Source Development 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 1

2 XTREME technologies: Development Strategy EUV-joint venture between Lambda Physik AG & Jenoptik LOS GmbH Mission: Development, manufacturing and marketing of EUV sources for lithography and EUV technology development gas discharge produced plasma source laser produced plasma source 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 2

3 XTREME technologies : Development Strategy Gas Discharge Produced Plasma Source single α-tool β-tool HVM technology Laser Produced Plasma Source 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 3

4 MEDEA+ EUV Source Development Program Participants: Germany* XTREME technologies (coordinator) Philips Extreme UV Jenoptik Mikrotechnik Zeiss France Alcatel CEA Thales Project content: Investigation on solutions for EUV sources including their characterization and interfacing to first generation of EUVL production tools Technology: Gas discharge produced plasma Laser produced plasma *funded by German Ministry of Education and Research (BMBF) Research topics: EUV sources for lithography EUV sources for metrology purposes (mask inspection, optics characterization, process development) Metrology for EUV source characterization 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 4

5 Outline 1. Laser Produced Plasma EUV Source Update 2. Gas Discharge Produced Plasma EUV Source XTS for Integration in EUV Microstepper 3. Performance Update High Power Gas Discharge Produced Plasma EUV Sources 4. Summary and Roadmap For results with tin see V. Borisov et al., Session Source 2, Wednesday 01 Oct. 03, 16:35, this conference 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 5

6 Most Critical Tasks in Source Development today 1. Increase optics lifetime / reduce debris - by orders of magnitude - HVM requirement > pulses at > 7,000 Hz 2. Increase power / improve efficiency HVM requirement 115 W in focus 3. Keep the heat-load (per area) manageable / improve cooling / increase components lifetime - by orders of magnitude - HVM requirement > pulses at > 7,000 Hz 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 6

7 Calibrated EUV Source Metrology Characterization of LPP and GDPP EUV sources is done by standard source diagnostics is calibrated at Bessy and/or cross calibrated at XTREME s EUV sources and comprises: Energy/ energy stability/ power monitor Pinhole camera EUV spectrometer EUV energy monitor E-Mon EUV pinhole camera EUV spectrometer 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 7

8 Laser Produced Plasma EUV Sources 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 8

9 LPP EUV Sources 4 source target systems are currently operated to address different research topics development of: injection systems gas & cooling systems observation systems RGA & environmental studies Engineering of support systems Stable jet-targets generated with 3-rd generation injection systems Droplet generation demonstrated 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 9

10 LPP EUV Sources Laser delivers up to 500 W at 10 khz in a 2x diffraction limited beam High power driver laser EUV source chamber > 2 W power in 2π sr at Etendue matched plasma size, with 5 sr source collector module > 1 W in intermediate focus Xenon target 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 10

11 LPP EUV Sources: Efficiency Optimization the highest conversion efficiency today is 0.95% optimization of coupling parameters leads to improved efficiency 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 11

12 LPP EUV Sources: EUV Energy Stability High EUV stability has been achieved with directionally stable Xe-targets EUV-energy / a.u Event probability 100 repeatability shot to shot Pulse # repeatability shot to shot EUV-energy / a.u. EUV-energy / a.u dose-stability 50 pulses moving average Time / seconds Pulse to pulse repeatability: σ (EUV energy) 4.7 % σ (Laser) 3.8 % Average CE: 0.82 % Max. CE: 0.94 % Dose stability: σ (energy dose) 0.88 % 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 12

13 LPP EUV Sources: EUV Source Dimensions EUV-Plasma dimensions Single pulse / filtered PH-camera Laser beam direction: 230 µm (1/e²) Xe-target direction: 270 µm (1/e²) 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 13

14 LPP EUV Sources: EUV Optics Lifetime Data Witness plate reflectivity is monitored during exposure / plate is analyzed afterwards MLmirror Plasma Photo diode Zr-foil h [nm] Target chamber abgedeckter Bereich große Blende kleine Blende kleine Exposure Blende 2 Exposure 1 große Blende Shadow abgedeckter Bereich Si Mo Si Mo Si Mo Si Mo Si Mo Si Mo Si b [µm] Life an EUV-inband energy of 0.6mJ: - 4* mbar (erosion of 10 multi layers) - with buffer gas up to 10 7 pulses do not cause any erosion at all 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 14

15 LPP EUV Sources: Power Upgrade MOPA + pre-amp + two identical 4 head power-amp chains > 1.3 kw, almost diffraction limited, short-ns pulses Target chamber for 1.5 kw laser 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 15

16 Gas Discharge Produced Plasma EUV Source XTS for Integration in EUV Microstepper 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 16

17 Gas Discharge Produced Plasma Z-Pinch EUV Source Principle Z-Pinch with pre-ionization surface discharge discharge unit Working gas Xenon Liquid cooling gas flow preionization unit plasma Interface to application and pumping unit Input energy up to 10 J/pulse z-axis cathode anode Highly stable output C0 L1 L2 Power supply C1 C2 switch 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 17

18 GDPP EUV Source XTS for EUV Microstepper EUV OUTPUT POWER / W/2%bandwidth solid angle 2π sr 1.8 sr EUV sources shipped Source power > 35 W in 2π solid angle REPETITON RATE / Hz Control / power supply unit EUV source head Diagnostic / interfacing vacuum chamber Pulsed power / gas supply More than 10 Gas Discharge Produced Plasma EUV sources have been built 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 18

19 GDPP EUV Source XTS for EUV Microstepper GDPP Sources XTS delivered to EXITECH, Oxford, UK for integration into Micro Exposure Tool MS-13 Equipped with debris mitigation and integrated with collector optics from Zeiss, GER Use for process development at International SEMATECH, USA See also poster # 170, Philipp H. Grünewald et al., EXITECH, Microstepper for EUV Lithography, and Poster #56, Udo Dinger et al., Carl Zeiss SMT, Fabrication and Metrology of Diffraction Limited Soft X-ray Optics for EUV Lithography 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 19

20 GDPP EUV Source XTS for EUV Microstepper EUV spectrum from Xtreme source (XTS 13-35) Spectral intensity [arb. units] 1,0 0,8 0,6 0,4 0,2 0, Spectral intensity [arb. units] 12,0 12,5 13,0 13,5 14,0 14,5 15,0 Wavelength [nm] Spectral distribution after Mo/Si multilayer mirror reflection Wavelength [nm] Intensity of 13.5 nm lines comparable to 11 nm lines Overall conversion efficiency (EUV output in 2π sr / stored electrical energy): > 0.55 % 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 20

21 XTREME s GDPP Source Component Lifetime Component EUV in-band Lifetime power versus > 100 Million pulses Pulses at 1000 Hz at > 35 mj / pulse and > 35 W power EUV Power [W / 2π sr] With power stabilization simulation EUV Source XTS Lifetime increase because of progress in Plasma wall distance increase Number of Pulses / Million 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 21

22 Lifetime Limits - Calculated Electrode Temperature T / K Evaporation due to deposited energy T melt (Tungsten) 3650 K T max 1000 Parameters: 500 Deposited energy 0 Tungsten layer thickness Cooling temperature Repetition Rate t / microseconds 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 22

23 Lifetime Limits - Calculated Electrode Mass Loss mass loss/shot / arb. Units Measured Calculated Evaporation due to deposited energy Repetition rate ( khz) 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 23

24 Lifetime Limits - Calculated Electrode Lifetime 1.00E+11 electrode lifetime (shots) 1.00E E E E+07 Evaporation due to deposited energy Plasma wall distance 3d Plasma wall distance d Plasma wall distance d/3 1.00E Repetition rate / khz 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 24

25 Debris and Optics Lifetime Debris Fast particles (ions, atoms) from plasma have dominant effect on optics lifetime today - lead to sputtering Material from electrodes (GDPP) or nozzle (LPP) is currently negligible but will become of importnce in future Debris aggressivity similar for GDPP and LPP Debris filter 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 25

26 Optics Lifetime On-line Measurements with Grazing Incidence Optics Turbopump Layer sensor monitor installed Source Source point Debris filter Oscilloscope Grazing incidence mirror sample Ref-EM EM Measures change in mass due to sputtering and/or deposition On-line reflectivity measurement with energy monitor (EM) Measures change in mass due to sputtering and/or deposition Pressure Measurement Distances Source point-sample 110mm Sample-detector entrance 450mm Sample aperture 11x15mm² Entrance aperture detector 5mm 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 26

27 Debris and Source Collector Optics Lifetime Thickness of Sputtered Layer / nm Without Debris Mitigation With Debris Mitigation 0,1 1E-3 0,01 0, Number of Pulses / Million Progress in debris filter arrangement and operation: Suppression of sputtering by fast particles at surface of collector optics by approximately 5000 times < 2 nm layer sputtered of after 10 million pulses at 35 mj EUV in 2π sr 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 27

28 XTREME s GDPP Source Collector Optics Lifetime 1.4 Normalized Reflectivity Debris filter Number of Pulses / Million Optics Lifetime > 50 Million pulses at 35 mj / pulse 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 28

29 Performance Update High Power Gas Discharge Produced Plasma EUV Source Development 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 29

30 Cooling Improvement for Z-Pinch GDPP Source Coolant: water Standard cooling design (09/01) (cooling fins) Maximum cooling capabilities: Anode 4.4 kw Cathode 2.6 kw Total cooling power 5.2 kw Cathode Ceramic insulator Anode Improved cooling design (10/03) (porous metal) Maximum cooling capabilities: Anode 7.9 kw Cathode 7.6 kw Total cooling power 15.2 kw 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 30

31 XTREME s GDPP EUV Source Power Improvement 120 W CONTINUOUS OPERATION 1.5 mm 0.5 mm Chuck Gwyns optimistic estimate at this conference: 207 W continuous Power in 2π sr are needed! 120 W power in 2π sr at Etendue matched plasma size > 10 - > 20 W in intermediate focus assuming % collector module efficiency 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 31

32 Power improvement of XTREME s GDPP sources Collectable EUV in-band power / W/2πsr Z-pinch PLEX FCI measurements CONTINUOUS OPERATION Power out of plasma volume: < 1.3 mm x 1.6 mm XTREME technologies Z-Pinch small plasma Porous metal cooling Aug 99 Mrz 00 Okt 00 Apr 01 Nov 01 Mai 02 Dez 02 Jun 03 Jan 04 date 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 32

33 Summary - LPP EUV Sources LPP EUV Sources EUV power of 2 W in 2π sr at 3300 Hz continuous operation Conversion efficiency up to 0.95% Source diameter 250 microns (1/e 2 ) Source energy stability of 5% sigma Optics lifetime (10 % reflectivity decrease) without debris mitigation is 4*10 6 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 33

34 Summary - GDPP EUV Sources XTS for EUV Microstepper EUV sources with 35 W in 2π sr at 1000 Hz delivered and under integration Optics lifetime (10 % Reflectivity decrease) with debris filter > 50 million pulses High Power GDPP EUV Sources EUV power of 120 W in 2π sr at 4000 Hz continuous operation > 10 - > 20 W in IF Conversion efficiency up to 0.55% Source dimensions 500 microns x 1500 microns (FWHM) Source energy stability of < 5% sigma 2nd International Extreme Ultra-Violet Lithography (EUVL) Symposium, Sept. 30 Oct. 02, 2003, Antwerp, Belgium Page 34