Toward 5nm node ; Untoward Scaling with Multi-patterning

Transcription

1 1 st International Symposium on DSA Toward 5nm node ; Untoward Scaling with Multi-patterning 27 th OCT 2015 H. Yaegashi Chief Engineer Tokyo Electron Limited

2 Down-caling trend towards N5 N20 N14 N10 N7 N5 H. Yaegashi Leuven BE

3 Opportunity and Crisis in future patterning H. Yaegashi Leuven BE

4 Opportunity and Crisis in future patterning H. Yaegashi Leuven BE

5 1D layout design fabrication flow Grating-line formation Line-cutting Contact hole fabrication H. Yaegashi Leuven BE

6 Grating-line formation with Multi-patterning SADP 44nm hp 22nm hp SAQP 11nm hp SAOP 5.5nm hp H. Yaegashi Leuven BE

7 Line-cutting width narrowing 193 cut mask N10 gate N7 gate N5 gate NTD trench 40-50nm Cutting 20nm 14nm 10nm 49.5nm 18.9nm 13.2nm 9.0nm 20nm H. Yaegashi Leuven BE

8 Scaling trend of Hole pattern N20 N11 N7 N5 33nmΦ / 42hp 18nmΦ / 23hp 12nmΦ / 15hp 9nmΦ / 11hp CD:38nm CD:11nm H. Yaegashi Leuven BE 11

9 Hole pitch shrink thru Multi-patterning Cross-SADP SADP SADP Etch Depo./Etch Line Lattice Hole/Pillar Hole Hole 16nm hp Pillar H. Yaegashi Leuven BE 12

10 Opportunity and Crisis in future patterning H. Yaegashi Leuven BE

11 ~ Pattern fidelity ~ Grating line thru Multi-patterning Short trench pattern for line-cutting Hole pattern H. Yaegashi Leuven BE 14

12 ~ Pattern fidelity ~ Grating line thru Multi-patterning Short trench pattern for line-cutting Hole pattern H. Yaegashi Leuven BE 15

13 Trend of observation area with down-scaling CDU across Wafer On-Chip variation Region of interest (Microscopic observation) CDU=1.31nm/3σ CDU=0.75nm/ 3σ H. Yaegashi Leuven BE 16

14 Pattern placement error on pitch-shrunk line SADP scheme Core-pattern Spacer-depo. Etch-back & Strip Edge of design H. Yaegashi Leuven BE

15 EPE deviation correcting result Control 6 EPE variation Control Improved Placement Error (3σ nm) Improved on 22nm hp H. Yaegashi Leuven BE

16 EPE deviation correcting result in detail Placement Shift Edge Variation 6 Placement Error (3σ nm) Control Smoothed Placement Shift Edge Variation H. Yaegashi Leuven BE 20

17 LER / LWR behavior thru SADP SADP scheme Core-pattern Spacer-depo. Etch-back & Strip SADPed pattern 1000 Core pattern LER LWR 1000 LER LWR LWR PSD (nm 3 ) SADP LER: 2.75 nm LWR: 4.37 nm Spatial Frequency (nm -1 ) H. Yaegashi Leuven BE LER: 2.66 nm LWR: 1.38 nm Spatial Frequency (nm -1 )

18 Effect of Smoothed mandrel Post Litho. SADP SAQP Fault case LER : 3.4nm LER : 2.4nm LER : 2.5nm Successful case LER : 1.9nm LER : 1.6nm LER : 1.4nm H. Yaegashi Leuven BE 22

19 Mask error factor improvement by LER suppression 1000 LWR PSD (nm 3 ) 100 Post Litho. Smoothing-1 Smoothing-2 Smoothing Spatial Frequency (nm -1 ) MEEF Post Litho Post Smoothing Aerial Image LWR PSD (nm 3 ) 100 Post Litho. Smoothing-4 Smoothing Spatial Frequency (nm -1 ) Mask hp CD (nm) H. Yaegashi Leuven BE 23

20 Affection of Image blur Aerial image PEB latent image Resist profile H. Yaegashi Leuven BE 24

21 LER affection on local-cduniformity LWR PSD (nm 3 ) Spatial Frequency (nm -1 ) 1000 Post Litho. Smoothing-1 Smoothing-2 Smoothing-3 Local CDU (nm) Post litho LWR PSD (nm 3 ) 100 Post Litho. Smoothing-4 Smoothing Spatial Frequency (nm -1 ) LWR (nm) H. Yaegashi Leuven BE 25

22 LER on 193-i resist pattern Resist A Resist C Resist E LER: 1.7 nm Resist B LER: 2.9 nm Resist D LER: 3.1 nm Resist F LER: 2.0 nm H. Yaegashi Leuven BE LER: 2.4 nm LER: 2.3 nm

23 LER reduction on various resist type LER (nm) Resist-A Resist-B Resist-C Resist-D Resist-E Resist-F Post Litho. Post smoothing H. Yaegashi Leuven BE

24 LER reduction on various Smoothing process LER (nm) Smotthing A Smotthing B Smotthing C Smotthing D Smotthing E Smotthing F Smotthing G Post Litho Post Smoothing H. Yaegashi Leuven BE

25 Limitation of LER suppression LER (nm) Post Litho Post Smoothing H. Yaegashi Leuven BE 29

26 ~ Pattern fidelity ~ Grating line thru Multi-patterning Short trench pattern for line-cutting Hole pattern H. Yaegashi Leuven BE 30

27 Patten fidelity on Line-cutting pattern 40nm H. Yaegashi Leuven BE 31

28 Smoothing effect in hole-shrink process Hole shrink M 0 C/H Hole shrink with Smoothing H. Yaegashi Leuven BE 32

29 Short trench pattern layout Test pattern Realistic pattern H. Yaegashi Leuven BE 35

30 Edge placement error correction Fault case Successful case H. Yaegashi Leuven BE

31 ~ Pattern fidelity ~ Grating line thru Multi-patterning Short trench pattern for line-cutting Hole pattern H. Yaegashi Leuven BE 39

32 CD-Healing effect on hole-shrink process Post Litho Post hole-shrink Post Healing Post Hole-shrink w/healing H. Yaegashi Leuven BE 40

33 CD-Healing effect on hole-shrink process ADI ADI Hole-shrink ADI CD Healing ADI CD Healing Hole-shrink 4.0 CER (nm) hole CD(nm) H. Yaegashi Leuven BE 41

34 Hole pattern restoration 68nm pitch case Resist Image Post H/M Etch H. Yaegashi Leuven BE 42

35 CD Measurement accuracy 40nm Φ 30nm Φ 25nmΦ 20nm Φ ADI Hole shrink amount Local CDU 7.2nm CER 2.1nm Local CDU 5.4nm CER 1.5nm Local CDU 3.7nm CER 0.9nm Local CDU 2.0nm CER 0.4nm Edge contouring Local CDU 7.1nm CER 2.6nm Local CDU 5.7nm CER 2.5nm Local CDU 5.5nm CER 2.2nm Local CDU 6.7nm CER 2.1nm H. Yaegashi Leuven BE 43

36 Opportunity and Crisis in future patterning H. Yaegashi Leuven BE

37 Process Complexity in Multi-patterning Grating line : SAQP ~ OP Line-cutting : LE^3~4 Contact hole : LE^3~5 H. Yaegashi Leuven BE 45

38 Process step number comparison 193 Extension EUV DSA 1D layout 1D layout 2D layout M 2 M 2 M 2 Layer via 1 Cut 1 via 2 Cut 2 via 3 Cut 3 via 4 Cut 4 Layer via 1 Cut 1 via 2 Cut 2 via 1 via 2 M 1 SAQP M 1 SADP M 1 Mask Mask Mask level : 8~10 layers Etch step : 12~ steps Mask level : 6 layers Etch steps : 6 steps Mask level : 4 layers Etch step : 4 steps Mask level :??? Etch step :??? H. Yaegashi Leuven BE 46

39 Process cost comparison via Line-cut Grating line CoC (a.u.) SADP SAQP SAQP +1CUt SAQP +3Cut SAQP +3Cut+2via SAQP +4Cut+4via EUV +via EUV +Cut+via EUV/SADP +2CUt+2via DSA + Process scheme EUV: 150WPH H. Yaegashi Leuven BE 50

40 Summary Scalability Spacer type multi-patterning is regarded as reliable technique that can extend 193 immersion. Pattern fidelity LER suppression plays important roles in fidelity control. Stochastics mignt drive pattern fidelity in N5 era. Cost / Process complexity Mitigation of process complexity remains biggest challenge. H. Yaegashi Leuven BE 51

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