Extension of 193 Immersion Lithography - Sokudo

NIKON PRECISION INC. 

Extension of 193 Immersion 

Lithography 

Steve Renwick 

Senior Principal Engineer, NPI

Overview 

• EUV Status 

• Bridging to EUV 

• Scanner Requirements for DP 

• NSR-S620D Performance 

SOKUDO Breakfast Forum July 14, 2010 2

Lithography Technology Roadmap 

65 

45 nm HP 

45 

32 

22 

16 

32 nm HP 

Water Water Immersion Immersion 

S609B 

NA 1.07 

S610C 

NA 1.30 

22 nm HP 

16 nm HP 

Double Double Patterning Patterning 

S620D 

NA 1.35 

ITRS DRAM ½ Pitch (nm) 

EUVL EUVL 

11 

2007 2010 2013 2016 2019 2022 


EUV Infrastructure Schedule 

Mask infrastructure 

development begins 

Mask tool availability: 

Chan, et al., SPIE 2010, February, 2010 

ITRS 

DRAM 

½ Pitch (nm) 

65 

45 

Aggressive 

DRAM 

32 

22 

Aggressive 

Logic 

Aggressive 

NAND 

1-2 years required for defect 

learning (immersion experience) 

HVM Process Development can 

begin here. 

16 

Mask tools available, 

defect learning begins 

11 

2007 2010 2013 2016 2019 2022 

Delays in infrastructure continue to push out adoption of EUV 

increased cost and longer ROI for equipment makers 


Extension of 193i Before EUV Arrives 

• Extend single patterning: 

– Source mask optimization and custom illumination 

• Enable 32 nm half pitch and beyond 

– Spacer double patterning 

– Pitch splitting double patterning (LELE, LFLE, etc.) 

– Line cutting lithography 

Tool makers need to support these schemes 


Line Cutting Litho Concept 

44 nm HP 

Patterning 

Spacer 

Pitch Doubling 

Target 

22 nm SRAM 

Gate Cell 

Cut Hole 

Patterning 

 

Hole Chemical 

Shrink 

After Etch 

 

 


Line Cutting Lithography Concept 

+ 

 

1 st patterning 

(LS formation) 

2 nd patterning 

(Cut) 

Result 

C. Bencher, et al., SPIE 72740G (2009) 

Down to 19 nm half pitch can be achieved 


S620D – Enabling the Next Generation 

• Enabling Superior Yield: 

– Overlay accuracy to enable DP 

– CD uniformity 

• Enabling Affordable Lithography: 

– Reduced wafer overhead time 

– Maximum throughput 

– Low CoO via multi-generational use of the tool 

• Enabling Rapid Production Ramps: 

– Faster installation 

– Optimal uptime 

– Platform to enable reuse 


The NSR-S620D Challenge 

NA 1.35 

Projection 

Lens 

Streamlign Platform 

for 2 nm 

self overlay 

Bird's Eye 

Control 

for 200 wph 

throughput 

Stream 

Alignment 

for 20 day 

installation 

Modular 2 

Structure 


Bird’s Eye Control 

Enabling Superior Yield 


• Hybrid system uses laser 

encoders w/interferometers 

• Dramatically improves 

accuracy and stability 

• Targeting 2 nm overlay 

capabilities 

• Superior focus control 

Enabling Affordable Lithography 

Enabling Rapid Production Ramps 

Stream Alignment 

Modular 2 Structure 





• Five-Eye FIA 

• Straight Line Autofocus 

• Greatly reduced wafer 

overhead time 

• Targeting throughput up to 

200 wph 








• Faster installation - 20 day 

target 

• Simplified maintenance 

• Optimal uptime 

• Extendible platform to 

enable reuse 







Scanner Requirements for DP 

32 nm hp DP Budget 

Budget 

Spec 

Line 

CDU 

Space CDU 

L1 − L 2 

CDU (3σ 

) 

1.0 nm 

2.4 

2.9 nm 

OL 

m − 

1 

m 

2 

0.5 

3.3 nm 

OL 

(3σ 

) 

2.4 

CD control and overlay are critical for DP 


S620D Overlay Stability 

Overlay average within lot 

Total 3σ 

3σX 

1.94 

3σY 

1.80 

[nm] 

ave.[nm] 

5 

4 

3 

1 2 

-1 0 

-2 

-3 

-4 

-5 

1 3 5 7 9 11 13 15 17 19 

Ave.X 

Ave.Y 

• 20 wafers continuous exp. 

• Common linear terms 

removed 

3sigma[nm] 

5 

4 

3 

2 

1 

wafer count 

Overlay 3sigma within lot 

3sigma.X 

3sigma.Y 

0 

1 3 5 7 9 11 13 15 17 19 

wafer count 

S620D meets overlay requirements for 32 nm hp DP 


Focus Uniformity 

14.3 nm, including edge die 

3σ [nm] 

20 

10 

14.8 15.0 14.9 

0 

1 2 3 

wafer # 

-50 nm 

50 nm 


Budget vs. S620D Data 

32 nm hp DP Budget and Actual Data 

L1 − L 2 

∆CD 

m1 − m 2 

∆OL 

Budget Spec 

1.0 nm 1.1 

2.4 2.1 

0.5 0.7 

2.4 1.9 

Line 

CDU 

2.9 nm 

2.5 

Space CDU 

3.3 nm 

3.3 

S620D data meet the budget requirement 


S620D Overall Performance 

Line CDU (3σ) 

Space CDU (3σ) 

2.5 nm 

3.3 nm 

22 nm L/S 

Line 1 

Line 2 

Space 1 

Space 2 

S620D enables pitch splitting DP 


Extendible Platform for ArF Immersion 

Modular 2 Structure allows multigenerational use 


Summary 

• The industry needs an interim solution for the 

32 nm and 22 nm nodes, prior to the HVM 

development of EUV 

• 193 immersion lithography will be extended by: 

– Source optimization and computational lithography 

– Double patterning 

– Multiple patterning and cutting lithography 

• This places severe new requirements on a scanner 

for overlay and CD uniformity 

• The Nikon S620D enables superior yield, affordable 

lithography, and rapid production ramps for 32 nm - 

with extendibility to 22 nm

Extension of 193 Immersion Lithography - Sokudo

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