Akira Miyake, Chidane Ouchi, International EUVL Symposium, October , Kobe Slide 1

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1 Development Status of Canon s EUVL Exposure Tool Akira Miyake, Chidane Ouchi, Hideki Morishima, and Hiroyoshi Kubo Canon Inc. International EUVL Symposium, October , Kobe Slide 1

2 Outline EUVL Exposure tool Roadmap Optics Evaluation Technologies Multilayer Evaluation Wavefront Error (WFE) Measurement Evaluation Results of PO1 Mirrors Surface Figure Multilayer (phase shift distribution) Optical Performance WFE and Resolution High-NA Projection Optics Exposure System Technologies Spectral purity filter (SPF) Optics Contamination Mitigation Summary International EUVL Symposium, October , Kobe Slide 2

3 EUVL Exposure Tool Roadmap ITRS DRAM 1/2pitch (nm) Flash 1/2pitch (nm) HVM Platform HVM tool (VS2) NA 0.33 OAI HVM tool (VS3) NA > 0.4 TP Enhancement Timing of the HVM tools is under consideration. Prototype SFET Installed at SELETE 6-mirror (PO1) NA0.3 In-house test International EUVL Symposium, October , Kobe Slide 3

4 Evaluation Technology At-wavelength Multilayer Evaluation System Mirror chamber Sample chamber Monochromator Controller EUV source Reflectivity measurement Phase measurement Polarization control Measured Reflectivity Field Intensity Electric Incident Beam Reflected Beam Vacuum Photoelectrons Multilayer Surface Si Mo Si Mo Si Mo Si Mo Depth (nm) photoelectron t intensity it depends d on phase difference between incident beam and reflected beam. M2 M1 M3 Sample P-pol Rotation S-pol extinction factor <1E-3 International EUVL Symposium, October , Kobe Slide 4

Evaluation Technology Wavelength Calibration Real-time wavelength calibration Primary standard: Krypton

source spectrum are measured simultaneously.

Electron Beam splitter (plane grating) CCD 1 Electron Multiplier Schematic view of the beam intensity

5 Evaluation Technology Wavelength Calibration Real-time wavelength calibration Primary standard: Krypton absorption lines Secondary standard: d Xenon emission lines Reflectivity of multilayer mirror and source spectrum are measured simultaneously. beam intensity monitor CCD 2 Multilayer Sample Monochromatic EUV light 1st order 0th order Kr gas cell Electron Beam splitter (plane grating) CCD 1 Electron Multiplier Schematic view of the beam intensity Monitor Using the Real-time wavelength calibration method, wavelength precision can be maintained constantly. International EUVL Symposium, October , Kobe Slide 5

6 Evaluation Technology EUV Reflectometer Round-RobinRobin EUV reflectometer cross calibration (Round-Robin) conducted by Selete participant: i t Selete, Canon, HOYA, NIKON, PTB S-pol. θ = 6deg Difference between Canon and PTB CWHM : <1pm Peak Reflectivity : <0.2% Measurement results by Canon and PTB show good agreement. Poster:ML-P05 M. Amemiya et al., Selete, Canon, HOYA, NIKON, PTB International EUVL Symposium, October , Kobe Slide 6

7 Evaluation Technology WFE measurement using low brightness source Tlb Talbot tinterferometer t (conventional) PO Single Pinpole spherical wave MISTI (Multi Incoherent Source Talbot Interferometer) t ) PO MISMask (Pinhole arrays) Spherical wave from pinhole arrays are incoherent. MIS Mask Illumination Optics Distorted spherical wave 2-D Grating 2-D Grating Projection Optics EUV Source fringe pattern Wavefront error of the PO can be derived from analyze of the fringe pattern. fringe pattern Position of fringe pattern is maintained. EUV flux is multiplied by number of the pinholes.( X10 5 ) CCD Grating Changeable Wafer Wafer Chuck WFE of PO can be measured using light source for exposure Applicable for on-machine measurement of projection optics WFE International EUVL Symposium, October , Kobe Slide 7

Evaluation Technology Experimental results of WFE Measurement EUV source Optics Chamber Experimental Tool using 2-Mirror PO 0 Repeatability of WFE:0.

Optical elements (MIS mask, Grating, Illuminator) are re-aligned for each measurement. WFE of a PO was measured using a compact DPP source.

8 Evaluation Technology Experimental results of WFE Measurement EUV source Optics Chamber Experimental Tool using 2-Mirror PO 0 Repeatability of WFE:0.028nmRMS 028nmRMS Fringe pattern 0.4 1st 2nd 0.2 3rd Zernike coefficient exposure time : 5sec WFE was measured 3 times. Optical elements (MIS mask, Grating, Illuminator) are re-aligned for each measurement. WFE of a PO was measured using a compact DPP source. Repeatability of WFE : 28 pm rms This experiment was performed as a collaboration work of Canon, Nikon and University of Electro-Communications. International EUVL Symposium, October , Kobe Slide 8

9 Results of PO1 Mirrors Mirror Surface Accuracy Power Spectrum Density Surface roughness Map 1E nm ② ④ ① ⑦ ③ -0.5nm ⑧ 250mm Measured roughness (pmrms) Area Measuring Point Figure: 40pmRMS 1E-2 MSFR: 61pmRMS 1E-3 1E 3 1E-4 Mirror No.2 No 2 Figure: 38pmRMS 1E-5 Average ② ③ ④ ⑤ ⑥ ⑦ ⑧ Φ5.0mm Φ0.77mm Φ0.15mm nm Range 120mm -5nm MSFR: 53pmRMS 1E-6 HSFR: 74pmRMS +5nm 1E-7 1E-8 ① 16 60mm 28 80mm ⑤ Powe er [nm2* *mm] ⑥ 80 0mm NA 60mm 1E Mirror No.1 HSFR: 65pmRMS Range -5nm Spatial Frequency [1/mm] Improved polishing technology on large-area EUV mirrors have been demonstrated. The technology meet the 5% flare specification in decades in spatial frequency. 9 International EUVL Symposium, October , Kobe Slide 9

radial position ML Thickness Distribution Phase Shift Distribution Thickness variation 0.

10 Results of PO1 Mirrors Mo/Si multilayer coating Multilayer thickness distribution and reflection phase shift distribution of a mirror of projection optics were evaluated. radial position ML Thickness Distribution Phase Shift Distribution Thickness variation 0.032% Uncorrectable phase error 2mλ Multilayer y Coating performance necessary for HVM exposure tool is achieved. International EUVL Symposium, October , Kobe Slide 10

11 Optical Performance Wavefront Error of a 6-Mirror Projection Optics Wavefront error of 0.33NA projection optics is estimated based on evaluation results of PO1 Mirrors. In the estimation, following factors are considered. mirror surface figure errors based on measured data of PO1 mirror coating errors based on measured data of PO1 mirror alignment errors of mirrors (positions, tilt) Estimated wavefront error (WFE) Map 2mm 26mm Z4-36RMS (worst) : 0.5 nm for 33 fields International EUVL Symposium, October , Kobe Slide 11

Optical Performance Estimated performance for hp16nm 1 NA0.33 PO with Off Axis Illumination (OAI) Illumination condition 0.8 0.6 0.4 0.2 0-0.2-0.4-0.6-0.8-1 -1-0.5 0 0.

2 (16nm pattern ) x hgt= 1 x hgt= 2 x hgt= 3 x hgt= 4 x hgt= 5 x hgt= 6 x hgt= 7 x hgt= 8 x hgt= 9 x hgt= 10 x hgt= 11 y hgt= 1 y hgt= 2 y hgt= 3 y hgt= 4 y hgt= 5 y hgt=

12 Optical Performance Estimated performance for hp16nm 1 NA0.33 PO with Off Axis Illumination (OAI) Illumination condition σout=0.8 σin = Pattern L/S=16 nm NILS nm Focus(nm) DOF >200nm for NILS>1.2 (16nm pattern ) x hgt= 1 x hgt= 2 x hgt= 3 x hgt= 4 x hgt= 5 x hgt= 6 x hgt= 7 x hgt= 8 x hgt= 9 x hgt= 10 x hgt= 11 y hgt= 1 y hgt= 2 y hgt= 3 y hgt= 4 y hgt= 5 y hgt= 6 y hgt= 7 y hgt= 8 y hgt= 9 y hgt= 10 y hgt= 11 Performance of NA0.33 PO was estimated. Predicted t d resolution is enough for 16nm pattern printing. International EUVL Symposium, October , Kobe Slide 12

13 Optical Performance High NA PO Design NA NA0.5 8 mirrors NA0.25 NA0.3 NA mirrors 4 mirrors hp32 hp23 hp16 hp11 NA International EUVL Symposium, October , Kobe Slide 13

14 System Technology Spectral Purity of LPP Source Spectral purity part of Joint Requirements for EUV Source Source Charqacteristic Spectral purity: [nm] (DUV/UV) 400 [nm] (IR/Vis) including 10.6 μm (3) (3) Assuming 10.6 mm being the excitation laser wavelength Requirement <1% at wafer values at IF-design dependent <10 100% at wafer values at IF-design dependent Joint Requirements for EUV Source Nikon, ASML, Canon EUVL symposium 2009 Measured out-of-band spectrum Parameter, Dimension OOB EUV (5-130nm excluding On Band ) at IF VIS-NIR(400nm-1.5 mm) Measurement conditions or Measured Data 3.3% for EUV band from 9 to 21 nm DUV( nm) % 0% of IB in pas plasmaa Cymer Inc. Igor V. Fomenkov (extrapolation of exponential fit) et al, Proc. SPIE IR (1.5-10μm) 10.6μm Reflection 6% of IB in plasma. MLM has low R for this band <0.01% in plasma using exponential fit 50% of Inband EUV Assumptions 10.6mmradiation at IF : 50% (ratio to in-band EUV) Mirror Reflectivity@13.5nm : 65% Mirror Reflectivity@10.6μm : 90% Number of reflection :12 Estimated IR wafer is 25X of in-band EUV. Number of reflection : 12 Spectral purity filter eliminating 10.6μm radiation is needed for CO2 Laser LPP source. International EUVL Symposium, October , Kobe Slide 14

15 System Technology Spectral Purity Filter Reflection type spectral purity filter (ML coated blazed grating) 50μm dsinα - dsinβ = mλ α d β θ 13.5nm 10.6μm In ntensity (arb b) 20 m= m= d 80um α 7deg θ 2deg N 10 0 次強度分布 13.5nm 1 次 m= μm α = 15deg 1 d = 50μm 0.9 系列 1 θ EUV = 3deg Grating Parameters Incident angle α Diffraction Angle (deg) Diffraction angle β Grating gpitch d Braze angle θ Diffraction order m A reflection type blazed grating can work as a spectral purity filter eliminating 10.6μm radiation. Advantage t of heat load durability 次回折 m= International EUVL Symposium, October , Kobe Slide 15

16 System Technology Optics lifetime/carbon deposition Mitigation Carbon deposition on EUVL exposure tool optics degrades throughput and imaging quality. Mitigation method of carbon deposition has been developed. Mitigation effect of oxidizing gas carb bon deposit tion rate(nm m/hr.) HVM Tool EUV intensity O 2 H 2 O O2 +O decane(~e-6 Pa)+O 2 (1E-2 Pa) decane(~e-6 Pa)+ H 2 O(1E-2 Pa) decane(~e-6 Pa)+ [O 2 +O 3 ](1E-2 Pa) EUV source: NewSUBARU Sample: [Si(4.2nm)/ Mo(2.8nm) ] 50 Irradiation time: 3 hr. average EUV intensity(mw/mm2) O 2 +O 3 is effective as the mitigation gas in the region of HVM Tool EUV intensity. This experiment was performed as a collaboration work of Canon, Nikon and University of Hyogo. Poster:OC-P06 T. Nakayama et al.,canon, NIKON, LASTI International EUVL Symposium, October , Kobe Slide 16

17 Summary Key technologies for HVM EUVL exposure tools have been developed. Multilayer evaluation (reflectivity, phase shift) Wavefront measurement using low brightness source Mirror figuring and ML deposition satisfying HVM tool requirements Reflection type spectral purity filter Mitigation of carbon deposition Timing of HVM EUVL exposure tools is under consideration. International EUVL Symposium, October , Kobe Slide 17

18 Acknowledgment Parts of this work were performed under the management of Extreme Ultraviolet Lithography System Development Association (EUVA) in the Ministry of Economy Trade and Industry program supported by New Energy and Industrial Technology Development Organization (NEDO). International EUVL Symposium, October , Kobe Slide 18

19 Thank you for your attention! International EUVL Symposium, October , Kobe Slide 19

Nikon EUVL Development Progress Update

Nikon EUVL Development Progress Update Takaharu Miura EUVL Symposium September 29, 2008 EUVL Symposium 2008 @Lake Tahoe T. Miura September 29, 2008 Slide 1 Presentation Outline 1. Nikon EUV roadmap 2.