Negative tone development process for double patterning

Transcription

1 Negative tone development process for double patterning FUJIFILM Corporation Electronic Materials Research Laboratories P-1

2 Outline 1. Advantages of negative tone imaging for DP 2. Resist material progress for negative tone development 3. Process maturity of negative tone development 4. Summary 5. Acknowledgement P-2

3 Outline 1. Advantages of negative tone imaging for DP 2. Resist material progress for negative tone development 3. Process maturity of negative tone development 4. Summary 5. Acknowledgement P-3

4 Overview of double patterning processes Double Exposure Double Development Freezing Spacer Defined Double Line Double Trench Resist Coat Resist Coat First Resist Coat Resist Coat Resist Coat Resist Coat First Exposure Exposure First Exposure Exposure Exposure Exposure Second Exposure First Dev. First Dev. Dev. Dev. Dev. Dev. Second Dev. Freezing Etching Etching Etching Second Resist Coat Sidewall form Resist Coat Resist Coat Second Exposure Etching Exposure Exposure Second Dev. Etching Dev. Dev. Etching Etching P-4

5 Trench pattern formation with DP Double trench process Double line process First Litho First Etch CD-L1 Alignment Second Litho CD-T1 CD-T2 CD-T1 CD-T2 Second Etch Double trench process CD-T1 Causes of CD error of CD-T1 P-5 CD-L2 Double Line process CD-L1, CD-L2, Alignment error CD error of trench pattern: Double trench process << Double line process (Freezing process)

6 Advantage of negative tone imaging in trench pattern printing NA = 1.2, Immersion (Water), Y Oriented Polarization, Dipole Radius: nm Pitch 1:3 Pattern Simulation NILS Bright Mask Line: Posi Resist Trench: Nega Resist Dipole Center Sigma NILS Dark Mask Line: Nega Resist Trench: Posi Resist Dipole Center Sigma Much higher optical image contrast can be obtained with negative tone imaging P-6

7 NTD, the first immersion exposure High frequency LWR (Mask: 64 nm 1:1 B / W) Posi Nega Resist: FAiRS-9521A01 Developer: FN-DP nm Trench (128 nm Pitch) 1.2 NA, dipole 64 nm 1:1 binary mask 4.3nm 3.2nm 32 nm Trench (128 nm Pitch) 4.2nm P-7

8 NTD, the first immersion exposure Low frequency LWR (Mask: 64 nm 1:1 B / W) Posi Nega 45 nm Trench (128 nm Pitch) Rectangle scan X: 150k, Y35k 5.5 nm 3.8 nm 32 nm Trench (128 nm Pitch) Rectangle scan X: 150k, Y35k P nm

9 A factor of lower LWR number at NTD Low swelling character with combination of conventional ArF resist and NTD QCM analysis result ΔFreq[Hz] mJ 3.0mJ 4.0mJ 4.3mJ 4.6mJ 5.0mJ 6.0mJ Dev.Time[s] P-9

10 Other feasibility, C/H printing by double exposure Obtained by double line exposures (horizontal and vertical) 1.20NA (ASML XT:1700i) 90 nm pitch, dense C/H X 96 / y 380 nm pitch, chain C/H Joost Bekaert (IMEC), et. al., See DS-02, September 24, this symposium. P-10

11 Outline 1. Advantages of negative tone imaging for DP 2. Resist material progress for negative tone development 3. Process maturity of negative tone development 4. Summary 5. Acknowledgement P-11

12 Issue with first resist platform, FAiRS-9101A01 Micro bridge at fine trench 45 nm trench μm μm μm B.F μm μm μm 32 nm trench P-12

13 Hypothesis of micro bridge at top of resist pattern Hypothesis 2: Swelling during development or rinse Δ Impedance, ohm Negative development 0.0 mj 1.0 mj 3.0 mj 4.0 mj 4.6 mj 5.0 mj 6.0 mj 20.0 mj Hypothesis 1: Lowered dissolution rate at surface Count of protection unit Film Surface QCM analysis Negative development rinse 100 TOF-SIMS analysis for de-blocking ratio Film Inside Depth from film surface, nm 0.0 mj 5.0 mj 10.0 mj 20.0 mj Δ Impedance, ohm Positive development 0.0 mj 2.0 mj 4.0 mj 6.0 mj 7.0 mj 8.0 mj 10.0 mj Development time, sec Development time, sec P Development time, sec

14 Surface localization properties for several PAGs Surface localization properties after PEB by ESCA method Relative acid concentration ratio indicates the ratio of the amount after PEB to that before PEB. Relative acid concentration ratio Conventional PAG PAG-C PAG-B PAG-A Some kinds of PAG showed very small concentration property at PEB step PEB Temperature P-14

15 Improvement by suppressing acid localization at film surface 32nm Target 9521A01 Conventional PAG 9521A01A New PAG-A 9521A01B New PAG-B LWR 4.7 nm LWR 4.2 nm LWR 4.8 nm 1.2NA, dipole illumination P-15

16 Mask linearity data FAiRS-9521A01 64nm Mask 60nm Mask 56nm Mask 52nm Mask 48nm Mask 44nm Mask 1.2NA, dipole illumination 37.8 mj/sq.cm FAiRS-9521A01A 64nm Mask 60nm Mask 56nm Mask 52nm Mask 48nm Mask 44nm Mask P-16

17 LWR at optimized SB/PEB condition (1.2NA, dipole condition) 32nm trench at 128nm pitch LWR = 4.1 nm Rectangle scan LWR = 2.4 nm Eop = 37 mj / cm2 Exposure latitude = 18% MEEF = 0.8 P-17

18 Resolution at optimized SB/PEB condition (1.2NA, dipole condition) 44nm trench at 88nm pitch Eop = 21 mj / cm2 Exposure latitude = 25% LWR = 4.5 nm P-18

19 Dense trench performance with 1.35 NA, dipole illumination 38nm HP, 1:1 W/B mask 22 mj / cm 2 24 mj / cm 2 26 mj / cm 2 28 mj / cm 2 30 mj / cm 2 32 mj / cm 2 44 mj / cm 2 42 mj / cm 2 40 mj / cm 2 38 mj / cm 2 36 mj / cm 2 34 mj / cm 2 EL=29.2% Bridge margin: 33% Collapse margin: >36% P-19

20 Dense trench performance with 1.35 NA, dipole illumination 38nm HP, 1:1 W/B mask, 30 mj / cm μm μm μm μm Best Focus μm μm μm μm P-20

21 Outline 1. Advantages of negative tone imaging for DP 2. Resist material progress for negative tone development 3. Process maturity of negative tone development 4. Summary 5. Acknowledgement P-21

22 CD uniformity data, FAiRS-9521A01 NTD Mean CD Wafer number R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C x STD-Dev Resist: FAiRS-9521A01 Developer: FN-DP001 45nm trench / 128nm pitch NA1.2, dipole illumination Dynamic dev-1 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C11 W-1 W P-22

23 CD uniformity data, FAiRS-9521A01A NTD and PTD NTD Developer: FN-DP001 Dynamic dev-1. 45nm trench 128nm pitch NA1.2 dipole illumination PTD Developer: OPD5262 Dynamic dev-2. R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C11 W NTD PTD Mean 43.8 nm 42.6 nm 3 x STD dev. 3.3 nm 4.0 nm R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C11 W R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C11 W Mean 42.7 nm 41.2 nm 3 x STD dev. 4.2 nm 5.1 nm R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 C-11 C-9 C-7 C-5 C-3 C-1 C1 C3 C5 C7 C9 C11 W P-23

24 CD uniformity and LWR uniformity with 1.35 NA NTD Developer: FN-DP001 Dynamic dev-1. frequency CD, nm 43 nm trench 90 nm pitch NA1.35 dipole illumination NTD PTD Mean 43.2 nm 43.3 nm 3 x STD dev. 1.6 nm 1.4 nm frequency PTD Developer: OPD262 Static dev CD, nm frequency LWR, nm Mean 4.8 nm 5.3 nm 3 x STD dev. 1.1 nm 1.2 nm frequency LWR, nm P-24

25 Outline 1. Advantages of negative tone imaging for DP 2. Resist material progress for negative tone development 3. Process maturity of negative tone development 4. Summary 5. Acknowledgement P-25

26 Summary 1. Advantage in trench CD uniformity of double trench process was discussed, and negative tone development (NTD) process was proposed as the best candidate for fine trench printing. 2. Micro bridge of original platform FAiRS-9521A01 is no longer critical issue by control of PAG localization after PEB at film surface. New platform FAiRS- 9521A01A was released. 3. FAiRS-9521A01A demonstrated 88 nm pitch resolution with 1.2 NA immersion exposure, and 76 nm pitch resolution with 1.35 NA immersion exposure. 4. Process maturity of NTD process was studied with CD uniformity comparison with positive tone development process. Quite promising initial results of 3-4 nm three sigma was obtained without any optimization of process. P-26

27 Acknowledgement Dr. Roel Gronheid, Dr. Mireille Maenhoudt, Dr. Joost Bekaert at IMEC. Junichi Kitano, Tsuyoshi Shibata, Kathleen Nafus, Shinichi Hatakeyama, Steven Scheer, Carlos Fonseca, Takafumi Niwa at Tokyo Electron. Grozdan Grozev, Mario Reybrouck, and Veerle Van Driessche at FUJIFILM ELECTRONIC MATERIALS (EUROPE) N.V. P-27