High-power DPP EUV source development toward HVM

Transcription

1 High-power DPP EUV source development toward HVM Yusuke Teramoto, Zenzo Narihiro, Daiki Yamatani, Takuma Yokoyama, Kazunori Bessho, Yuki Joshima, Takahiro Shirai, Shinsuke Mouri, Takahiro Inoue, Hiroshi Mizokoshi, Gohta Niimi*, Tomonao Hosokai*, Hironobu Yabuta, Kohkan C. Paul, Tetsu Takemura, Toshio Yokota, Kiyoyuki Kabuki, Koji Miyauchi, Kazuaki Hotta, and Hiroto Sato Gotenba Branch, Hiratsuka Research and Development Center Extreme Ultraviolet Lithography System Development Association (EUVA) *Ushio Inc Komakado, Gotenba, Shizuoka , Japan Phone: +81-(0) , Fax: +81-(0) This work is supported by New Energy and Industrial Technology Development Organization (NEDO). 1

2 Outline Evaluation of Sn-fueled DPP source at/after intermediate focus A potential solution for obtaining sufficient source power for HVM Debris shield and cleaning Summary 2

3 Source power for 50-W W demonstration 800 In-band EUV power (W/2pisr) Sn-fueled DPP source Two types of electrode tested W obtained Type A Type B Reliability Plasma shape Collection efficiency PRF (khz) 430-W source selected for comprehensive IF performance evaluation 3

4 Sn-fueled DPP EUV source system for 50-W W demonstration Tin fuel supply HV charger (G6) Source control unit Pulser & DPP head Collector chamber Aperture / Filter Power monitor Angular distribution monitor CCD Debris shield Collector Cleaning device 4

5 IF metrologies Discharge head Debris shield Collector ND filter Spectral filter (12.4~16 nm) X-ray CCD Z-axis Source IF CCD position aligner Position aligner Irradiance distribution at IF plane Aperture (φ 4.6 mm) Spectral filter (12.4~16 nm) Visible light VIS CCD IF Approximate far-field image 5

6 IF metrologies Discharge head Debris-shield Collector Spectral filter Aperture (φ 4.6 mm) Thermal detector Source Position aligner Aperture (φ 4.6 mm) I.F. Spectral purity at IF In-band radiation sensor unit filter Mo/Si mirror PD I.F. In-band angular distribution IF Optical axis 6

7 Irradiance distribution at IF (a) Simulation (b) Measurement Simulation Measurement Irradiance profile Radius-flux curve 7

8 Approximate far-field field image Simulation Vertical profile 30-deg. profile Vertical 30 deg. simulation measurement Measurement Radial profile Radius-flux curve 8

9 Angular distribution after IF 500 Radiation intensity [a.u.] Simulation Measurement (Detail mode) 0 Decrease possibly due to debris-shield obscuration Angle from axis [degree] Angular distributions of simulation and measurement 9

10 In-band power at IF: 19 W of average power measured Simulation 25 Measurement Radiant intensity [mj/sr, 2%BW] Measurement Usable power [W, 2%BW] Simulation Etendue = 3.3 mm 2 sr Angle from axis [degree] Solid angle [sr] Angular distributions of simulation and measurement Output angle dependence of in-band energy after IF 10

11 In-band energy stability: <0.5 % achievable In-band EUV energy [a.u.] 3.5E E E E E E E E+00 5 khz, after IF Integrated energy stability (100 pls, σ): 4.6 % Pulse # EUV energy [a.u] Feedback control (Simulation) Integrated energy stability (100 pls, σ): 0.47 % Pulse # In-band energy stability at 5 khz 11

12 Spectral purity at IF: DUV is ~1 % of in-band 5nm~120nm : 99.7% nm(2%BW) : 28.9% Ratio to 13.5nm [%] nm~400nm : 0.29% 400nm~ : 0.02% nm (2%BW) nm nm > 400 nm All Fraction of each wavelength band Ratio to 13.5nm radiation 12

13 Measured IF power: 19 W average Evaluation item Experimental result Irradiance distribution at IF plane EUV Well consistent with simulation results Approximate far-field image EUV Well consistent with simulation results Distribution profile (Inband) Nearly consistent with simulation results Angular distribution Spectral purity In-band power In-band energy stability (Integrated over 100 pulses) Energy ratio to 13.5nm ±2%BW Average : 19.1 W / 3.3 mm 2 5 khz Free running : σ = 4.6 5kHz FB controlled : σ = 0.47 % [simulation] After 4.6mm 5kHz 5 ~ 120 nm : 244 % 120 ~ 400 nm : 1.0 % 400nm ~ : 0.1 % All (w/o filter) : 345 % Source : Tin-fueled Z-pinch DPP source Collector : Multi-shelled grazing-incidence mirror (assembly with debris-shield) Metrology : All in-band energy detectors were cross-calibrated with E-Mon 13

14 HVM and beyond: constant increase of power required Required power (W) Increasing with generations Minimum power requirement (Joint Spec.) in high-volume manufacturing >3x higher power than present level As throughput increases, power requirement also increases. Present level EUV power Thermal load Electrode lifetime Higher conversion efficiency Higher collection efficiency Higher input power (PRF and E/pulse) ~ Spread thermal load ~ 14

15 A potential solution: Laser-Assisted DPP Pulsed power driver Rotating electrode - spread thermal load - equivalent to large-surface-area electrode Laser - fuel delivery to the discharge Tin fuel - located somewhere in the source Pulsed power driver - energy input to the discharge Laser for fuel delivery Rotating electrodes CONCEPTUAL diagram of laser-assisted DPP source 15

16 Scalability study: linear scaling up to 10 khz confirmed Energy (J) 24 T=100 us (f=10 khz) 13.5 In-band EUV power (W/2pisr) [a] Time (us) 300 [b] PRF (khz) [a]10-khz stable charge/discharge operation was confirmed on 150-kW system. [b]source power increases in almost proportional to PRF up to 10 khz. Construction of 20-kHz system in progress targeting 1~2 kw/2πsr of in-band EUV power. 16

17 Power-related related study: 790 W achieved at 6 khz In-band EUV power (W/2pisr) % 790 W CE (%) φ0.5xl0.7 mm (FWHM) PRF (khz) Stability CE Improvement Plasma shape Linearity at >7 khz Power input Energy per pulse Repetition frequency HVM source power 17

18 Debris treatment: important in any types of source Discharge gas EUV source TMP TMP P-QCM Sample Mirror Collector mockup (12 dummy shells) uffer gas Dummy Shells In-situ cleaning test cycle SnH 4 DPP operation Sn deposition on mirror Mirror reflectivity measurement Cleaning gas (Cl) Photodiode Pin-hole Halogen Cleaning Sn removal from mirror Mirror reflectivity measurement 18

19 Debris treatment: cleaning works effectively 110 Normalized reflectivity Sn deposition Cl cleaning Cleaning cycle (time) Cleaning of mirror samples on the dummy shell After 63 cycles of cleaning, relative reflectivity remains >90 %. CC-P02: Debris mitigation and mirror cleaning for Sn-fueled EUV source 19

20 Summary and future works Summary Evaluation of intermediate focus on Sn-fueled source Power: 19 W confirmed. Collection performance: experimental data consistent with simulation. OoB: data showed enough less contribution of DUV. Source development for >HVM Power: 790 W at 6 khz. Scalability: tested up to 10 khz, resulted in good scalability. Future works Continuation of IF evaluation Development of 20-kHz discharge system Improvement of rotating-electrode DPP source performance 20