1. Directed Self Assembly of Block Copolymers
December 2017
Directed Self Assembly of Block Copolymers
Aigerim Galyamova
Chemistry Graduate Student

2. Outline Motivation Concept Processes Process flow Comparison
Challenges

3. Motivation: Moore’s Law

4. Motivation: Physical Limitations
Approaching limits for all parameters:
k = 0.3 (0.15 for SADP)
For EUV: λ = 13.5 nm
Tool complexity and cost increase

5. Concept: Block Copolymers
Orientation problem
Alignment problem
Holes and Islands!

6. Concept: Block Copolymers

7. Concept: Directed Self Assembly
Graphoepitaxy: physical constrains
alignment by topographic guiding force
Chemoepitaxy: chemical constrains
alignment driven by surface energy

8. Concept: Graphoepitaxy
BCP assembly within the trench
Topographic substrate patterning

9. Concept: Chemoepitaxy
Epitaxial assembly upon chemical pattern
Chemical Pattern consistent with BCP

10. Process: Directed Self Assembly
LiNe
SMART
Hybrid
Chemoepitaxy
Combination

11. Liu-Nealey: LiNe Process
PS-b-PMMA
100 nm full pitch;
35 nm line
193 nm lithography; PTD

12. LiNe Process
MAT etch and trim
100 nm full pitch;
15 nm line
PR strip

13. Neutral Brush spin coat
LiNe Process
Neutral Brush spin coat
PS-b-PMMA
BCP spin coat

14. LiNe Process
BCP annealing
12.5 nm line/space
L0 = 25 nm
PMMA removal

15. SMART: Surface Modification for Advanced Resolution Technology Process
PS-b-PMMA
90 nm pitch;
45 nm line
193 nm lithography; NTD

16. SMART Process
Neutral Layer etch
90 nm pitch;
45 nm line
PR strip

17. SMART Process Pinning Material spin coat Pinning Material brush
90 nm pitch;
45 nm line
Pinning Material brush

18. SMART Process
BCP spin coat
15 nm line/space
L0 = 30 nm
PMMA Removal

19. Comparison: LiNe vs SMART
PTD;
Pinning Material undergoes lithography step;
Neutral Layer spin coated afterwards;
Both use
[Ps-b-PMMA];
Both produce similar results;
SMART:
NTD;
Neutral Layer undergoes lithography step;
Pinning Material spin coated afterwards;

20. BCP: PMOST-b-PTMSS L0 = 20nm
Hybrid Process
BCP: PMOST-b-PTMSS L0 = 20nm
193 nm lithography; PTD
Guide: XPMOST

21. Guide Mmaterial etch and trim
Hybrid Process
BCP: PMOST-b-PTMSS
Guide Mmaterial etch and trim
Guide: XPMOST
PR strip

22. Neutral brush spin coat
Hybrid Process
BCP: PMOST-b-PTMSS
Neutral brush spin coat
Guide: XPMOST
Strip ungrafted brush

23. BCP spin coat, top coat spin coat
Hybrid Process
BCP spin coat, top coat spin coat
20 nm full pitch
PMOST removal

24. Comparison: Chemoepitaxy vs Hybrid
200 nm
Chemoepitaxy
Hybrid

25. Challenges Alignment control on large scale LER has to be improved
Within wafer
Wafer from wafer
LER has to be improved
200 nm

26. Summary: Directed Self Assembly
DSA:
Can be integrated within existing systems/tools
Low cost processes
CD controlled with polymer design
Pathway for new developments

27. Thank you for your attention!

28. References
Blachut, G. and Willson, C. (2016). A Hybrid Chemo-/Grapho-Epitaxial Alignment Strategy for Defect Reduction in Sub-10 nm Directed Self-Assembly of Silicon-Containing Block Copolymers. Chemistry of Materials, 28(24), pp
Kim, J. and Wan, J. (2013). The SMARTTM Process for Directed Block Co-Polymer Self-Assembly. Journal of Photopolymer Science and Technology, 26(5), pp
Garner, G. and Rincon Delgadillo, P. (2017). Design of surface patterns with optimized thermodynamic driving forces for the directed self-assembly of block copolymers in lithographic applications. Molecular Systems Design & Engineering, 2(5), pp

29. References
Nikonereview.com. (2017). DNP and AZ-EM Speakers Identify the Need for Lithography Paradigm Changes. [online] Available at: [Accessed 20 Nov. 2017].
Jeong, S. and Kim, J. (2013). Directed self-assembly of block copolymers for next generation nanolithography. Materials Today, 16(12), pp
Stoykovich, M. and Kang, H. (2007). Directed Self-Assembly of Block Copolymers for Nanolithography: Fabrication of Isolated Features and Essential Integrated Circuit Geometries. ACS Nano, 1(3), pp