EUV Masks: Remaining challenges for HVM

Transcription

1 EUV Masks: Remaining challenges for HVM Pawitter Mangat June 13, 2013

2 EUV Masks Challenge Pyramid Zero defect printability needs a lot of Mask supporting infrastructure HVM Storage Mask Lifetime Mask in-fab Use & Handling Defect Free Shipping &Handing Inspection, Repair and Phase Defect compensation Absorber patterning process with black border Defect mitigation by pattern shift/ blank rotation Low defect mask blanks with Fiducials (Location accuracy) June 13, 2013 EUV Litho Workshop, HI 2

3 EUV Mask Manufacturing flow-what is different? New Blank Supplier* Mask Shop * Assumes fiducials blanks Mask Data- OPC Flare, HV bias?? Blank Sorting Pattern Shift Blank orientation. Pattern Generator New Shift /Rotation Litho(e-beam) Confirmation (Coat/Bakes/Develop) Resist CD Metrology Absorber etch Resist strip New In Fab Handling NXE Exposure New BB Placement Metrology BB loop Metrology Litho(Alta)/ML etch/ Strip/Clean Repair/ Clean Clean Inspection Transfer/Shuffler to DP Redo loop (Optional) Storage Ship DP or RSP Final Audit Clean Inspection Redo loop (Optional) Transfer/Shuffler To DP/Ship Box New EUV AIMS Back Side Insp BB Repair (incl Comp) /Clean 3

4 Mask Blank Gaps/Challenges Fiducial Strategy and Blank Supply with fiducials SEMI P-48 task force Defect location accuracy relative to fidcuials Upfront Identification of blank defects that print Defects > 100nm Difficult to hide/repair by defect mitigation approach Primary cause is deposition process June 13, 2013 EUV Litho Workshop, Maui, HI 4

5 Fiducial SEMI P-48 draft under reconsideration June 13, 2013 EUV Litho Workshop, Maui, HI 5

6 Fiducial SEMI P-48 draft Supplier prespective June 13, 2013 EUV Litho Workshop, Maui, HI 6

7 20nm Integration Mask defect printability result Integration flows showing promising results for early confidence building but will not be sufficient For HVM Blank Sorting vs layout Blank orientation and pattern shift selection to hide blank defects under absorber (dark pattern) or fill region Identify critical area for defect hiding on the layout Printed without Repair; Only 1 repairable defect in critical area June 13, 2013 EUV Litho Workshop, Maui, HI 7

8 Average CD Error (Mask Scale 4x nm) Energy (ev/um 3 ) Mask Making-MPC EUV Electron Backscatter Electron backscatter from EUV mask blank material large compared to DUV masks This causes short range variation in printing Worst Case Example: Through pitch variation of absorber line Variation MUCH larger than 0.3nm error allowance Not corrected by state of the art mask writers Not (explicitly) modeled in OPC 1, Absorbed Energy in Resist (Simulated) Cr OMOG EUV Radius (um) Monte Carlo Simulation Performed with PENELOPE Pitch (Wafer Scale 1x nm) Paper SPIE Advanced Lithography MPC Absorber Line Through Pitch Avg. CD Error vs. Pitch CD 11 nm Linearity Error Measured Mask Data

9 Black Border-Added Challenges Additional mask process steps - added Cycle time Impacts Placement accuracy relative to die layout Defect Inspection within BB area Defect Inspection proximity to BB Area Role of cleans for mask lifetime Impact on CD Metrology (ESD/CD drift) T. Katai et. al, PMJ 2013 June 13, 2013 EUV Litho Workshop, Maui, HI 9

10 Mask Cleans- Maximizing Lifetime is essential Target >100 clean Cycles Opportunity for Dry Cleans to maximize lifetime Suss Mircotec Key Parameters: Ru Surface Roughness, Absorber Modification, Absorber CD control, EUV reflectivity, Front and Backside PRE June 13, 2013 EUV Litho Workshop, Maui, HI 10

11 Added Mask Lifetime Challenge-Back Side Mask Defectivity after exposure back side µm µm µm µm µm µm µm After clamp and clean µm µm µm µm µm µm µm 11

12 1 absorption length (nm)-1 New Opportunities-EUV masks Thin absorber Essential for EUV Extensibility HV Bias, Telecentricity (PP) Meet all current absorber requirements inc. Plasma etching Cleaning, Inspection, Repair Durability under exposure. Pellicle development Significant progress shown Need full integrated solution Adhesive, Outgassing Frame definition Inspection strategy Ni Ag Te Ta Levinson, SPIE 2013 EUV Litho Workshop, Maui, HI 12

13 EUV Masks Challenge Summary Zero defect printability needs a lot of Mask supporting infrastructure HVM Storage Mask Lifetime Mask in-fab Use & Handling (No pellicle) Defect Free Shipping &Handing Inspection, Repair and Phase Defect compensation, EUV AIMS Absorber patterning process with black border Defect mitigation by pattern shift/ blank rotation Low defect mask blanks with Fiducials (with defct Location accuracy) June 13, 2013 EUV Litho Workshop, HI 13

14 Summary EUV Litho Workshop, HI 14

15 Trademark Attribution GLOBALFOUNDRIES, the GLOBALFOUNDRIES logo and combinations thereof are trademarks of GLOBALFOUNDRIES Inc. in the United States and/or other jurisdictions. Other names used in this presentation are for identification purposes only and may be trademarks of their respective owners GLOBALFOUNDRIES Inc. All rights reserved.