From ArF Immersion to EUV Lithography

Transcription

1 From ArF Immersion to EUV Lithography Luc Van den hove Vice President IMEC

2 Outline Introduction 193nm immersion lithography EUV lithography Global collaboration Conclusions

3 Lithography is enabling 1000 ITRS Technology Trends MPU Gate Length Gate Length (nm) year Node Cycle 3-year Node Cycle Year Source: 2003 ITRS - Exec. Summary

4 Rayleigh equation Wave length scaling Lord Rayleigh resolution = k1. λ NA 193nm 157nm

5 157nm Challenges CaF 2 lens material Catadioptric lens design Fluorinated resist materials Mask technology Modified SiO 2 Surface contamination Pellicle: none / soft / hard transmission radiation hardness reticle heating Purging N 2 fill

6 Outline Introduction 193nm immersion lithography EUV lithography Global collaboration Status, Challenges, Outlook Conclusions

7 Rayleigh equation Lord Rayleigh resolution = k1. λ NA NA scaling

8 Immersion Lithography Improvements in resolution Snell s law : NA = η = 0 sin θ 0 = η f sin θ f η r sin θ r η glass n glass η 0 η f liquid η r

9 Immersion Lithography Improvements in resolution Snell s law : NA = η = 0 sin θ 0 = η f sin θ f η r sin θ r η glass n glass η 0 dry η f liquid η r

10 Immersion Litho Extremely short introduction time

11 Immersion demonstration in record time March 2002: Key note SPIE Santa Clara Burn Lin (TSMC): First suggestion to consider immersion lithography Mirror Fluid Inlet Vacuum Pump Fluid Replenishing Hole Last Lens Element Tank Cover Wafer Fluid Thermal Control Filter Fluid Outlet Mirror Drain

12 Immersion demonstration in record time March 2002: Key note SPIE Santa Clara Burn Lin (TSMC): First suggestion to consider immersion lithography October / November 2003: ASML and IMEC demonstrate feasibility on 0.75NA immersion prototype scanner First immersion scanning image on Oct 7, % EL Att PSM Att PSM BIN BIN DRY WET BIN > 50% DOF gain demonstration

13 Immersion demonstration in record time March 2002: Key note SPIE Santa Clara Burn Lin (TSMC): First suggestion to consider immersion lithography October / November 2003: ASML and IMEC demonstrate feasibility on 0.75NA immersion prototype scanner January 2004: Sematech Lithography Forum Los Angeles World momentum shifts entirely from 157nm to immersion lithography

14 Immersion demonstration in record time March 2002: Key note SPIE Santa Clara Burn Lin (TSMC): First suggestion to consider immersion lithography October / November 2003: ASML and IMEC demonstrate feasibility on 0.75NA immersion prototype scanner January 2004: Sematech Lithography Forum Los Angeles World momentum shifts entirely from 157nm to immersion lithography 193nm immersion 157nm

15 Immersion demonstration in record time March 2002: Key note SPIE Santa Clara Burn Lin (TSMC): First suggestion to consider immersion lithography October / November 2003: ASML and IMEC demonstrate feasibility on 0.75NA immersion prototype scanner January 2004: Sematech Lithography Forum Los Angeles World momentum shifts entirely from 157nm to immersion lithography End 2004: multiple 2 nd generation 0.85 NA immersion scanners have been shipped (TSMC, IMEC)

16 Immersion Lithography A few challenges Process interactions Defectivity Polarization effects Lens dimensions

17 Immersion Lithography A few challenges Process interactions Defectivity Polarization effects Lens dimensions

18 Process Interactions Interaction of resist/top coat with water

19 Process interactions Some topcoats reveal an intrafield CD fingerprint similar to the soak simulations Soak simulation CD fingerprint

20 Process interactions CD soak fingerprint using new developer soluble topcoats is significant reduced compared to TSP3A (but still visible) New developer soluble topcoats TSP3A TILC019 TCX007

21 Immersion Lithography A few challenges Process interactions Defectivity Polarization effects Lens dimensions

22 Immersion defectivity A spherical air bubble casts a shadow

23 Bubble Defects Simulated (2-beam imaging) aerial image of 500nm bubble defect on 100nm L/S pattern

24 Bubble improvement (/1250i) Non-optimized conditions After optimization

25 Immersion specific defects Scanner contributions Bubbles (related to shower head design, wafer chuck design, ) Defects (related to water residues, related to chuck/head design, ) Resist/process contributions Resist leaching (resist conposition, use of top coat, ) Hydrophobicity (material contact angle, material response to water droplets, ) Water quality (particles, bacteria, TOC, ) α = 70 α = 105

26 Immersion Lithography A few challenges Process interactions Defectivity Polarization effects Lens dimensions

27 Polarization at high NA X-polarized (TM) NA=0.6 Y-polarized (TE) Angle of incidence in resist Image contrast 70% 20 Image contrast 92% In tensity Medium NA NA (0.6) (0.6) in in resist resist (n=1.7) (n=1.7)

28 Polarization at high NA X-polarized (TM) NA=0.85 Y-polarized (TE) Angle of incidence in resist Image contrast 49% 30 Image contrast 92% High High NA NA (0.85) (0.85) in in resist resist (n=1.7) (n=1.7)

29 Polarization at high NA X-polarized (TM) NA=1.3 Y-polarized (TE) Angle of incidence in resist Image contrast -8% 50 Image contrast 59% Very Very High High NA NA (1.3 (1.3 immersion) in in resist resist (n=1.7) (n=1.7)

30 Contrast enhancement with polarization SRAM, half pitch 55 nm, pitch 110 nm, 6% att PSM, dipole Y Un-polarized 0.93 NA dry BE+6.6% BE+3.3% BE BE-3.3% BE-6.6% BE+15.4% BE+10.3% BE+5.1% BE BE-5.1% BE-10.2% BE-15.4% Polarized Design adjustments

31 Immersion Lithography A few challenges Process interactions Defectivity Polarization effects Lens dimensions

32 Hyper NA: lens cost

33 Hyper NA: lens cost 193nm lens 2003 G-line lens 1975 >1000 mm >300 mm

34 Cost innovations in Optics for hyper NA Expected according geometrical scaling dioptric Released or expected dioptric New catadioptric design Air Water Lens complexity i 1.1 i 1.2 i 1.3 i n air NA 1.43 i n water

35 Outline Introduction 193nm immersion lithography EUV lithography Global collaboration Status, Challenges, Outlook Conclusions