Progress towards Actinic Patterned Mask Inspection. Oleg Khodykin

Transcription

1 Progress towards Actinic Patterned Mask Inspection Oleg Khodykin

2 Outline Status (technical) of EUV Actinic Reticle Inspection program Xe based LPP source as bright and reliable solution Requirements Choice of architecture Current status Radiance Short bursts Long term at 100% DC Collector lifetime test setup Major sources of collector degradation Prototype current status Collector lifetime tests Xe recirculation Conclusions 2 KLA-Tencor Confidential - Internal Use Only

3 Status of EUV Actinic Reticle Inspection program

4 Latest Reticle Inspection Solution EUV patterned masks and blanks Optical; Complex OPC, Quartz etch reticles For 10nm Generation Teron 630 Practical sensitivity limited by edge roughness Industry proven sensitivity for advanced optical and EUV Mask applications 4 KLA-Tencor Confidential - Internal Use Only

5 EUV Reticle Defect and Inspection Challenges Pellicle transmission effects will narrow the wavelength choices Reflective Multilayer Coating Reticle Absorber pattern Pellicle Single pass spectral transmission Only EUV has enough transmission 5 KLA-Tencor Confidential - Internal Use Only

6 EUV Actinic Patterned Mask Inspection Tool EUV actinic inspection is a must for EUVL High Volume Manufacturing due to: Phase defects ML Blank defects Contamination defect risks Throughput Through-pellicle inspection 710 Program The world s only EUV Actinic Patterned Mask Inspection (APMI) System 6 KLA-Tencor Confidential - Internal Use Only

7 710 Program Summary System Architecture defined EUV-specific large format image sensor designed and tested Optics concepts provide large field and high transmission Xe LPP source prototype shows required lifetime Ultra-clean vacuum prototypes tested Pilot production facility ready for build-out Ongoing new component/subsystem test Program ready for full-scale development 7 KLA-Tencor Confidential - Internal Use Only

8 Xe based LPP source as bright and reliable solution

9 Actinic Patterned Mask Inspection - EUV source requirements Property/parameter Target Value Units Wavelength 13.5 nm, centroid Pulse repetition rate > 10 khz Pulse duration > 10 ns, FWHM Duty Cycle > 95% - minimum burst > 15 sec Etendue 1.0 x 10-2 mm 2 -sr Radiance at I/F > 20 W/mm 2 -sr (Averaged over etendue, lifetime) 2.2% band, pre-spf Footprint (m) 2.8W x 2.8D x 2.8H Availability > 95% Cost of Service (annual) < 10% Relative to CoGs / Price Cost of Operation (annual) < 5% 9 KLA-Tencor Confidential - Internal Use Only

10 Options method of plasma generation Method DPP LPP Advantages Simple Clean Small plasma size Scaling though repetition rate Disadvantages Erosion of near-plasma elements Large plasma volume Long plasma Low repetition rate due to pulse power limitations 10 KLA-Tencor Confidential - Internal Use Only

11 Options choice of target material Target Xe Sn Advantages Noble gas High CE (>3%) No deposition Disadvantages Can be pumped by off-shell turbo pumps Requires closed loop circulation due to high cost of Xe (10-30$/liter) Deposition Requires mass limited targets Numerous issues with stable and reliable droplet generation Reacts with Ru to form alloys 11 KLA-Tencor Confidential - Internal Use Only

12 Cryogenic rotating drum LPP source - Schematic of operation Dewar access tube Ice-covered drum is rotated and translated, presenting smooth ice surface for each laser pulse Drive / Vacuum Seal IR laser window Cryo drum (Cu) Drum housing (Al) Wiper (SS) LN 2 IR laser optics IR Laser (YAG) Frozen xenon layer Vacuum chamber 12 KLA-Tencor Confidential - Internal Use Only

13 Conversion Efficiency EUV source performance: short bursts 0.80% 0.70% 50% Laser Energy 100% laser Energy 0.60% 0.50% 0.40% 0.30% 0.20% 0.10% 0.00% Lens offset, mm 13 KLA-Tencor Confidential - Internal Use Only

14 EUV plasma image x vertical profile HW at 1/e 2 =59 mm x horizontal profile HW at 1/e 2 =78 mm KLA-Tencor Confidential - Internal Use Only

15 CE % Steady state EUV output E = 80 mj, DC = 93 %, Free run Time [sec] 15 KLA-Tencor Confidential - Internal Use Only

16 Long term: EUV signal, size, and 5kHz EUV signal (nvs)/brightness (W/mm 2 *sr) nVs 93.7um 9.25W/mm 2 sr Average Signal=30.8nVs (σ=1.7nvs) Average size=83.9 um (σ=4.8um) Average brightness=9.8w/mm 2 sr (σ=0.63w/mm 2 sr) ) Time(hours) Image Size (HW 1/e 2 ) EUV signal Brightness 29.3nVs 82.7um 9.47W/mm 2 sr Image size (mm) 16 KLA-Tencor Confidential - Internal Use Only

17 Primary collector damage mechanism Energetic ions/neutrals intrinsic to plasma formation Sputtering of MLM by direct energetic ions has been recorded with >200nm/hours erosions rates at 26cm from plasma Sputtering of plasma facing components and chamber walls (too close in LPP 1 setup) & re-deposition of sputtered material on collector Collector to plasma distance of 0.5-1m is required due to limit of clean pumping solutions. Concept of shower head collector with Ar flow has been successfully tested 17 KLA-Tencor Confidential - Internal Use Only

18 EUV Source Collector Lifetime (CLT) Setup Drum Target LN2 Laser Focusing Optics Imaging Tool TMP Power Tool Laser 18 KLA-Tencor Confidential - Internal Use Only

19 CLT setup details Support collector cm from plasma Advanced protection of collector and laser optic with distributed buffer gas flow Collector 40cm or 70cm Flexible debris mitigation capabilities EUV Source Plasma Laser focusing optics Plasma wall distance is > 0.5 m Up to 8 turbo-pumps can be installed with total throughput of 16slm IF interface ready Base pressure is at 2*10-8 torr 19 KLA-Tencor Confidential - Internal Use Only

20 Prototype current status 21-2B52 3nm-Ru-IOF B Ru-LBL B53 3nm-TiO B64 3nm-ZrO2 Duration -120 hours collector EUV Brightness (W/(mm 2 sr)) Time (Hours) Effective duty cycle - 80% (limit with current target %, manual LN2 and Xe bottles replacement) Radiance is at 8W/mm 2 in free run mode 0.55 NO reflectivity degradation (within 0.5% accuracy) IF 20 KLA-Tencor Confidential - Internal Use Only

21 Xe Recycling Development Options Parameter or Spec Vendor A Vendor B Vendor C General Technology Distillation and adsorption Distillation Multistep adsorption (room temperature, PSA/VSA) Main products Rare Gases, Equipment Rare Gases Technical Gases Critical specification parameters Recirculation efficiency >99% 95% 90% (RE>98%) Xenon Purity (99.999%) % >99.999% at >99.9% 95%RE Throughput Demonstrated Feasible Up to half of required per system Contaminations (spec) Demonstrated Feasible TBD Cost of Recirculation (<$0.6/liter) <$0.5/liter >$1.5/liter TBD Footprint <10m m 2 10m 2 Height <3m 4.5m 2m 21 KLA-Tencor Confidential - Internal Use Only

22 Xe recycle unit development: automatic control 22 KLA-Tencor Confidential - Internal Use Only

23 Conclusions Required radiance has been demonstrated at 10kHz in steady state Further radiance scaling is possible with faster drum (demonstrated) and repetition rate. Major collector degradation mechanisms have been fully characterized Effective debris mitigation strategies have been developed and tested Full week of operation at 5kHz and 80%DC have been completed with NO collector reflectivity degradation (<0.5%) -> collector lifetime at 10kHz is more than 2000hours. Efficient Xe recirculation system has been developed with >99% capture rate Xe and >99.999% Xe purity, which enable cost effective source solution. 23 KLA-Tencor Confidential - Internal Use Only

24 Thank You