Interference Assisted Lithography (IAL): A Way to Contain the Lithography Costs for the 32nm and 22nm Half-Pitch Device

1. Interference Assisted Lithography (IAL): A Way to Contain the Lithography Costs for the 32nm and 22nm Half-Pitch Device Generations Rudi Hendel; David Markle; John S. Petersen; Andrew Barada; Periodic Structures, Inc. Zhilong Rao Applied Materials, Inc.

2. Presentation Overview • Semiconductor Manufacturing Costs:A quick calibration • Cost Model OverviewBasics and Assumptions • Interference Assisted LithographyAn introduction into the Concept • Process and Lithography-related cost factors and their impact • Results and Discussion • Conclusions Periodic Structures, Inc. Lithography Extensions Conference, Prague

3. Pixel Transfer Rate “Lithography is a Bargain!*” * Paul Arnold, ASML at the VLSI Litho Panel 2008 (November 18, 2008) 450mm projections Periodic Structures, Inc. Lithography Extensions Conference, Prague

4. Still – Time for Reality Check: (Comparing the price-tag for a Fab with….) Megafab: $6B to $10B $5B $3B $1B Periodic Structures, Inc. Lithography Extensions Conference, Prague

5. Should the size of Fab Price Tags be a concern? Yes Bob Johnson (Gartner DQ) at ISS 2009 Periodic Structures, Inc. Lithography Extensions Conference, Prague

6. Tool component – Depreciation and Tool Maintenance Allocation of Mask Cost Process Cost (Resist, Develop, BARC, Metrology, Inspection, etc. The basis of our Cost Model: Model by “Screenivasan et al.” as quoted by Frank Goodwin, November 7, 2005 – Trends in the Cost of Photolithography Periodic Structures, Inc. Lithography Extensions Conference, Prague

7. Direct Impact Costs Cost and Complexity of the Patterning Process Cost of additional Tools required (ex.: S.I.T.) Cost of Mask(s) Depreciation Cost and Maintenance Expense of the Exposure Tool Tool Price to Customer Effective Throughput Scheduled & unscheduled Maintenance Indirect Impact Costs(Factors of high importance to a customer on which the Choice of Lithography has a critical impact) Cost of Design Time to Design Implementation Risk of First Silicon Fail Cost of Lithography Periodic Structures, Inc. Lithography Extensions Conference, Prague

8. Per Yan Borodovsky; Semicon West; July 15, 2009 Periodic Structures, Inc. Lithography Extensions Conference, Prague

9. Pixel Transfer Rate How to reduce cost? Start with the Tool Either: Simplify the pattern, reducing Pixel Transfer Rate which leads to lower capital cost Or: Trade off general purpose capabilitywith acceptable restrictionsleading to cost savings Periodic Structures, Inc. Lithography Extensions Conference, Prague

10. Effective Means to segment (and reduce) Information Content contained in a pattern: • Interference Assisted Lithography • It separates high frequency component of the image (dense line-spaces) from the design content (line-ends) • Simplified Imaging Rules allow lower tool cost • without sacrificing minimum resolution • Several technology approaches are available • Ultimate Selection will accommodate key requirements in both, logic and memory. Periodic Structures, Inc. Lithography Extensions Conference, Prague

11. What is Interference Assisted Lithography? • I.A.L. is a two-exposure process: • Exposure One – Fixed Pitch Pattern (a grating) • Exposure Two – a Block-Mask, determining where the lines defined in the first exposure end and start + = Periodic Structures, Inc. Lithography Extensions Conference, Prague

12. The I.A.L. Technology Principle has been demonstrated Source: MIT Lincoln Lab (2005) M. Fritze, T. M. Bloomstein, B. Tyrrell, T. H. Fedynyshyn, N. N. Efremow, D. E. Hardy, S. Cann, D. Lennon, S. Spector and M. Rothschild, “Hybrid Optical Maskless Lithography: Scaling Beyond the 45nm Node”, J. Vac, Sci. and Tech. B 23(6) (2005), pp. 2743–2748. Periodic Structures, Inc. Lithography Extensions Conference, Prague

13. Benefits of Interference-based Exposure Tools • Cost benefits • Simplified Optics and thus lower Tool Cost • OL requirements for IAL are relaxed compared to OL requirements for traditional Double Patterning • Significant savings in Cost of MasksIAL requires 1 critical mask,Double Patterning requires 2 + • Technical Benefits • Wider process window • Increased Contrast/DOF Periodic Structures, Inc. Lithography Extensions Conference, Prague

14. Double Patterning: – Comparing Traditional D.P. vs. I.A.L. D.P. The reduced Cost of Masksgives IAL DP a30% cost benefit compared to Traditional DP(Independent ofMask Usage) Periodic Structures, Inc. Lithography Extensions Conference, Prague

15. Total Litho Cost by Node:Assignment ofMask Levels Periodic Structures, Inc. Lithography Extensions Conference, Prague

16. Total projected Lithography CostTraditional D.P. vs. I.A.L. D.P. Traditional Double Patterning Cost of Lithography per Wafer I.A.L. Double Patterning Periodic Structures, Inc. Lithography Extensions Conference, Prague

17. Total projected Lithography Cost Hypothetical Case of replacing all EUV Layers with IAL Cost of Lithography for the Node Traditional Double Patterning I.A.L. Double Patterning Only I.A.L. DP for Critical Layers Periodic Structures, Inc. Lithography Extensions Conference, Prague

18. Additional Benefits Possible with I.A.L.(System Architecture Dependent) • Reduced Capital Cost benefits all Lot Sizes • In the case of a reduced Exposure Field (Not all applications require large Exposure Fields) • Further Mask Cost Reduction • Minimizing write/inspection costs • Particularly benefitting small lot sizes, which are highly sensitive to Mask Cost • Reduced Systems Cost (Stepper architecture allows systems simplifications) • Additional efficiency particularly for small devices (somewhat counterintuitive) Periodic Structures, Inc. Lithography Extensions Conference, Prague

19. Mask Cost vs. Mask Patterned Area Periodic Structures, Inc. Lithography Extensions Conference, Prague

20. Cost of Lithography Comparison – Traditional Scanner vs. I.A.L. Stepper Periodic Structures, Inc. Lithography Extensions Conference, Prague

21. I.A.L. Limitations • High Regularity requires Design Restrictions • I.A.L. Restrictions are similar to Sidewall Image Transfer (S.I.T.) Restrictions • Yet, S.I.T. is considered as one viable option for extending resolution. • Designs compatible with S.I.T. are expected to be compatible with I.A.L.. • Adopting such restrictions early and transitioning to regularity in one single step promises significant cost benefits. Periodic Structures, Inc. Lithography Extensions Conference, Prague

22. In Summary – Cost Benefits of I.A.L.: Direct: • Significant reduction of Mask Cost • Comparable layers (vs. traditional DP) • Containment of Litho Cost Increases • If applied to all Critical Levels in the process flow • Additional Benefits are possible: • Reduced Die Size, Small Lot-size, (leading to smaller Exposure Fields) • Enhanced Maskless Lithography Economics • Reduced Image (Pixel) Density for Block Mask • Enables competitive MLL Throughput (prototyping) Periodic Structures, Inc. Lithography Extensions Conference, Prague

23. In Summary – Cost Benefits of I.A.L.: Indirect: • I.A.L. can become a Technology Enabler for a market segment currently underserved: • Opening Access to Leading Edge Geometries for low/medium mask usage applications (ASIC/ASSP) by: • Reduced Mask Costs (and Capital Cost) • Simplified DR complexity • Reduced time to Design Completion • Reduced risk to first time success Periodic Structures, Inc. Lithography Extensions Conference, Prague

24. Acknowledgements • Al Bergendahl, Bergendahl Enterprises • Marc Levenson • Mark Pinto, Applied Materials • Hans Stork, Applied Materials • Bill Tobey, ACT Consulting Periodic Structures, Inc. Lithography Extensions Conference, Prague

25. Thank you! Periodic Structures, Inc. Lithography Extensions Conference, Prague