Nissan Chemical, ‐where unique & solution meet
Novel DDR process and materials meet NTD process
Materials Research LaboratorySemiconductor Materials Research Department
Shuhei Shigaki, Ryuji Onishi, Wataru Shibayama,Makoto Nakajima and Rikimaru Sakamoto
2015 International Symposium onExtreme Ultraviolet Lithography
October 5-7, 2015, Maastricht, The Netherlands
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 2
Pattern collapse issue
130nm 90nm 65nm 45nm 3Xnm 2Xnm 1Xnm
ArF imm.ArFKrF
Lithography technique
DPTEUVEB
The pattern collapse is common issue in all generation.
Xnm
ArF-dry EUV
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2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 3
Dry Development Process
L0 = 30nm
sc CO2
Wet Development
DSA (= Directed Self-Assembly)
【Pattern creation by Dry Etching】sc CO2 Dry Development
In Dry Development process, capillary force can’t work ⇒Dry Development technique was useful as the next gen. patterning.
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 4
About DDR process
PEB Replacement by DDR material
DDR material(Si based polymer)
Spin dry & Bake
PR
Mask
Etch back Dry development
No pattern collapse!Higher aspect ratio!
DDR process : Dry Development Rinse processDDR process : Dry Development Rinse process
Development& Rinse
Exposure
Nocapillary force!
Key Process
DDR process is the promising process as novel collapse free process.
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
DDR material: Dry Development Rinse material < Polymer + Solvent (+ Additive) >
DDR material was remained after etching
Solvent typeEtch Selectivity vs. PR
CF4 O2
Water (For PTD)1.3 - 1.8 <0.1
Organic (For NTD)
RyRx
Rx,y: Functional unit
After over coating (PTD case) After etching
Space areaPattern area
DDR material
PR
DDR materials
5
NTD-DDR process was newly demonstrated.
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
About NTD process
6
Exposure Baking (de-protection) Development
O OHn
PTD (TMAH aq.) NTD (Org. solv.)
Current NTD-PR showed higher resolution and lower LWR.
1) Proc. of SPIE Vol. 9425 942505-12) Proc. of SPIE Vol. 9048 90482C-73) Proc. of SPIE Vol. 9422 94220N-5
ArF 1) EB 2)EUV hp18nm 2) EB hp14nm 3)
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Issues of EUV-NTD lithography
7
Process liability evaluation for extreme ultraviolet lithography Hajime Aoyama, Kazuo Tawarayama et al.J. Micro/Nanolith. MEMS MOEMS. 8(4), 041508 (October 05, 2009).
Negative Tone Imaging had disadvantage when blight-mask was selected.→How to print blight image with NTD process ?
Defect on mask Printed image
Issues of EUV lithography
FlareIt will be more influenced when blight-mask was used.
Mask image Resist imageMask absorber roughness impact in extreme ultraviolet lithographyAlessandro Vaglio Pret ; Roel Gronheid et al.J. Micro/Nanolith. MEMS MOEMS. 10(2), 023012 (June 29, 2011).
Flare effect
Defect printingDefectMore defect will be printedby using blight-mask.
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2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 8
Merit of NTD – DDR process
Combination of DDR process & Negative Tone Imaging can overcomepattern collapse issue and blight image printing issue.
Target : iso-trench
BF
DF
Blight mask NTD image
NTDonly
DF
BF
Dark mask
NTD&DDR
NTD image NTD-DDR image
Pattern image got worsedue to flare effect…
Lowerflare effect
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
NTD – DDR process
9
Exposure Baking Development
PTD (TMAH aq.) NTD (Org. solv.)
NTD – DDR (Org. solv. → dry dev.)
◆Higher solubility for organic solvent ◆Good compatibility for NTD dev.(NBA)◆No-mixing property for NTD PR ◆high planarity on PR pattern
Requirement :
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Sample PTD-DDRM NCR535Application For PTD For NTD
Polymer
Functional unitR1,2 Higher solubility for DIW
Shelf life enhancementR3,4 Solubility for org. solvent
Shelf life enhancement
Solvent Water 100 Normal butyl acetate (NBA)
Etch Rate(vs. P.R.)
By CF4 gas 1.8 1.4
By O2 gas < 0.1 < 0.1
Solvent compatibility(Normal butyl acetate)
SiO
O Si OOx y
R2R1
10
DDR material for NTD process
R4R3
Clear !2 LayersClogging
DDRM
NBA
NCR535 for EUVL was newly developed.
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2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 11
Mixing check (ArF NTD-PR)
NCR535 kept original pattern quality.
DDRM / PRstacking
DDRM removeby NBA
Original ArF NTD-PRF.T. 80nm, L65P130
Pattern missing…
PR
DDRM
Ref. DDRM (Alcohol solv.)
NCR535(NBA solv.)
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Analysis of mixing layer
12
Flat exp.(ArF)
EUV-NTD PRSub.
PEBExposed PR
→ NCR535 CoatingNCR535F.T. 1
NCR535 removal(by NBA)
Dev. (NBA)
→ Baking (100degC./60s)Mixinglayer
Mixing layer was evaluated by F.T. measurement & XPS analysis.⇒If it’s mixing, Si atom would be detected on surface from NTD-PR.
F.T. 2
XPS analysis
F.T.1 ≠ F.T.2⇒ Mixing
F.T.1 = F.T.2⇒ No Mixing
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Analysis of mixing layer
13
NCR535 showed no-mixing property with NTD-PR.
Sample F.T.1Inital
F.T.2NCR535 removal
XPS (atom%)
C O Si
NTD-PR 68.4nm - 76.7 23.3 0.0
Ref. DDRM - - 26.6 51.9 21.5
NCR535 - - 26.6 51.9 21.5
Ref. DDRM/PR 68.4nm 24.4nm 57.9 26.7 15.4
NCR535/PR 68.4nm 67.2nm 72.6 26.1 1.3
Intensity of Si atom on PRafter NCR535 removal
NCR535 case:NTD-PR kept initial F.T.after NCR535 removal.
lower Si atom was detectedon NTD-PR surface.
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Planarity
14
Dark Field(Width: 10um)
Trench(Width: 800nm)
Depth: 220nmBare-Si Wafer
F.T.(DF) F.T.(T)
Reference
F.T. Bias: 124nm
NCR535
F.T. Bias: 40nm
Sample F.T.:【100nm】
F.T. Bias:【F.T.(DF) – F.T.(T)】
F.T.: 78nm
F.T.: 92nm
F.T.: -46nm
F.T.: 52nm
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Patterning (EB)
15
PR pattern (hp 20nm)PR FT: 40nm
DDR pattern (hp 20nm)PR FT: 50nm
Tone reverse pattern was obtained in hp20nm by NTD-DDR process.
SOC 20nm F.T. SOC 20nm F.T.NCR535 ~35nm
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Patterning (EB)
16
Clear pattern of hp17.5nm was created without pattern collapse.It couldn’t be obtained by normal process due to thicker F.T. of PR.
DDR pattern (hp 19nm)PR FT: 50nm
DDR pattern (hp 17.5nm)PR FT: 50nm
Nissan Chemical, ‐where unique & solution meet
2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands
Summary
17
New DDR material for NTD PR was developed.
Novel DDR material showed no mixing propertywith ArF & EUV NTD-PR.
Fine pattern below hp20nm was created by combination ofNTD process & DDR process.
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2015 International Symposium on Extreme Ultraviolet Lithography, Maastricht, The Netherlands 18
Acknowledgement
Thank you