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High-End EUV Photomask Repairs for Advanced Nodes

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High-End EUV Photomask Repairs for Advanced Nodes High-end EUV Photomask Repairs for advanced nodes Dr. Michael Waldow Product Manager vZTech - Virtual SMS Tech Conference, 18.05.2021 Agenda 1 Introduction 2 High-end EUV photomask repairs 3 Summary Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 2 Agenda 1 Introduction 2 High-end EUV photomask repairs 3 Summary Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 3 Introduction EUV High-Volume manufacturing ramping up SAMSUNG newsroom C. C. Wei – TSMC - CEO & Vice Chairman* MAY 21, 2021 JULY 16, 2020 “…new production line in Pyeongtaek, Korea…will produce 14- ‚Next, let me talk about our N5 ramp up and N4 introduction. N5 is the foundry nanometer DRAM and 5-nanometer logic, …based on EUV...” industry's most advanced solution with best PPA. N5 is already in volume Anandtech.com - APRIL 02, 2021 production with good yield, while we continue to improve the “… South Korea authorities this week gave SK Hynix a green light to build We are seeing robust productivity and performance of the EUV tools. a new, 120 trillion won ($106.35 billion) fab complex…. using demand for N5 and expect a strong ramp of N5 in the second half of this year, driven by both 5G smartphones and HPC applications.‘ process technologies that rely on extreme ultraviolet lithography (EUV)…’ ▪ EUV is becoming more and more important and Intel: The Empire Strikes Back** MAY 21, 2021 amount of EUV lithographic layers is rising ‚while the outlook on EUV was still quite uncertain. Hence, Intel's initial 7nm ▪ First consumer products based on EUV seems to have used EUV quite conservatively, in relatively few layers. Intel said the new 7nm process flow (as it has been developed since mid-2020) uses over technology are already on the market 100% more EUV. We have now fully embraced EUV", Pat Gelsinger said…’ ▪ On the other hand EUV photomasks possess the highest numbers of defects Sources **Q2 2020 Taiwan Semiconductor Manufacturing Co Ltd Earnings Call, Efficient and reliable way to repair high- **https://seekingalpha.com/article/4427816-intel-the-empire-strikes-back end photomasks is essential Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 4 Introduction – Photomask repair MeRiT® Mask repair technology Photomask repair tool MeRiT® at a glance Principle of operation ▪ MeRiT® neXT system is the industry-standard ▪ Exposure with focused electron beam for high-end photomask repair systems ▪ Adsorption of precursor molecules ▪ Enables the repair of smallest defects on todays’ photomasks Repair of opaque defects - etching Repair of clear defects - deposition Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 5 What is contributing to resolution of MeRiT® Tools Analogy: What contributes to draw with high accuracy? Analogy: Contributions to draw with high accuracy Ink Spilling Drawing Small Shiver/ Tremor Sharpness Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 6 What is contributing to resolution of MeRiT® Tools Transfer to MeRiT® technology - Electron beam as a pen and precursor molecules as ink Contributions to MeRiT® repair resolution Secondary Electrons Repair Resolution System E- Beam Jitter Spot Size Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 7 Contributing to resolution of MeRiT® Tools Main factor I to Repair Resolution – Secondary Electrons Secondary electrons as function of electron voltage 140% 120% [%] 100% 80% Electrons Secondary 60% Electrons 40% 20% Secondary 0% Repair 200 400 600 800 1000 1500 2000 Resolution Electron beam voltage [V] ▪ Scattered secondary electrons increase significantly with increasing voltages System Jitter E- Beam Spot Size Higher repair resolutions can be achieved by operation at lower electron beam voltages Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 8 Contributing to resolution of MeRiT® Tools Main factor II to Repair Resolution – Electron Beam Spot Size Beam spot size as function of electron voltage 140% [%] 120% size 100% spot 80% Standard column Secondary 60% Electrons beam 40% New column 20% Electron 0% Repair 200 400 600 800 1000 1500 2000 Resolution Electron beam voltage [V] ▪ In general electron beam column resolution decreases with System Jitter E- Beam decreasing voltage Spot Size For higher repair resolution a new column with a smaller beam spot size at given voltage need to be used Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 9 Contributing to resolution of MeRiT® Tools Main factor III to Repair Resolution – System Dynamics Tool jitter as as function of diffrent tool platforms Tool Jitter MeRIT tools 100% 75% Standard Tool Platform 50% [%] 25% Jitter 0% Secondary New Tool PLatform Electrons -25% -50% System System -75% -100% Repair 0 0,2 0,4 0,6 0,8 1 1,2 1,4 Resolution Time [s] ▪ MeRiT® repair resolution is detoriated by tool vibrations/jitter System E- Beam Spot Jitter Size In order to make use of full potential of new MeRiT® repair tools, system jitter has to be minimized Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 10 MeRiT® LE overview Next generation mask repair tool MeRiT® LE - What‘s new? 1. MeRiT® LE is operating at lower electron voltage ▪ Tool is optimized for lower energy of 400eV compared to MeRiT® neXT, which operates at 600eV 2. MeRiT® LE is equiped with a new electron beam column ▪ Tool is equipped with Low-kV Objective Lens optimized for low beam energies 3. Improved system jitter enabling highest repair resolution ▪ Re-designed tool platform including improved acoustic enclosure and improved tool damping Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 11 Agenda 1 Introduction 2 High-end EUV photomask repairs 3 Summary Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 12 High-end EUV photomask repairs MeRiT® repair and AIMS® EUV actinic measurements in the mask shop ecosystem Mask making process Pattern Metrology Tuning Inspection Disposition Repair Verification Cleaning Generation AIMS® EUV MeRiT® Repair AIMS® EUV 1 2 3 4 Defective Defect-free EUV mask EUV mask Printability test by Detailed analysis by E-beam mask repair Printability check AIMS® EUV technology high resolution e-beam by MeRiT® after repair by AIMS® EUV Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 13 High-end EUV photomask repairs EUV ETCH repair of bridge defect Defect Type: Bridge defect Bridge Defect ▪ Length 500nm ▪ Half-Pitch 60nm on mask Pre-repair SEM image MeRiT® LE repair MeRiT® LE Post-repair SEM image repair AIMS® EUV analysis Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 14 High-end EUV photomask repairs AIMS® EUV Analysis of bridge defect repair Post-repair aerial image by AIMS™ EUV Analysis of CD with AIMS™ Auto Analysis (AAA) Bridge Defect x MeRiT® LE repair y Shown results are at best focus Along center of defect ▪ Along the center of the defect the CD variation is below the CD variation of the reference structures AIMS® EUV analysis ▪ A maximum ΔCD of 2.6nm results for the repair Successful EUV bridge repair verified by AIMS® EUV Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 15 High-end EUV photomask repairs Small extrusion defect on a EUV photomask Defect Type: Extrusion Bridge Defect ▪ Length 500nm Analysis of CD with AIMS® Auto Analysis (AAA) ▪ Half-Pitch 88nm on mask 98 SEM defect image CD Along center of defect 96 ∆CD<10nm 94 Tiny <10nm 92 ® extrusion! AIMS EUV 90 printability test CD 0, opaque / nm 88 86 AIMS® EUV defect image 84 -500 0 500 Y position / nm MeRiT® LE repair ▪ Aerial image is clearly affected by tiny extrusion defect ▪ On average detected CD deviation from reference analysed to be smaller than 10nm Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 16 High-end EUV photomask repairs EUV ETCH repair of small extrusion defect Defect Type: Extrusion repair Extrusion Defect ▪ Length 500nm ▪ Half-Pitch 88nm on mask Tiny <10nm extrusion! ® Pre-repair SEM image MeRiT LE repair ® AIMS® EUV MeRiT LE Post-repair SEM image repair analysis Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 17 High-end EUV repairs AIMS® EUV Analysis of tiny extrusion repair ® Post-repair aerial image by AIMS® EUV Analysis of CD with AIMS Auto Analysis (AAA) Extrusion Defect 92 Repair 90 x 88 MeRiT® LE repair CD [nm] 86 84 y Shown results are at best focus Along center of defect 0 500 1000 1500 ▪ Along the center of the defect the CD variation is CD Center Y [nm] below the CD variation of the reference structures AIMS® EUV analysis ▪ A maximum ΔCD of 3.3nm results for the repair Successful tiny extrusion repair <10nm verified by AIMS® EUV Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 18 High-end EUV photomask repairs EUV DEPO broken-line defect repair Defect Type: Broken-line Broken Line Defect ▪ Length 500nm ▪ Half-Pitch 60nm on mask Pre-repair SEM image MeRiT® LE repair MeRiT® LE Post-repair SEM image AIMS® EUV repair analysis Carl ZEISS SMT GmbH, Dr. Michael Waldow, Semiconductor Mask Solutions 18.05.2021 19 High-end EUV photomask repairs AIMS® EUV Analysis of broken line defect repair Post-repair aerial image by AIMS™ EUV Analysis of CD with AIMS™ Auto Analysis (AAA) Broken Line Defect 62 61 x 60 59 MeRiT® LE repair 58 CD0, opaque / nm 57 y Shown results are at best focus 56 Along center of defect -800 -600 -400 -200 0 200 400 600 800 ▪ Along the center of the defect the CD variation is y / nm about the CD variation of the reference structures AIMS® EUV analysis ▪ A maximum ΔCD of 3.8nm results for the repair Successful EUV broken line repair verified by AIMS® EUV Carl ZEISS SMT GmbH, Dr.
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