Nissan Chemical, ‐where unique & solution meet Nov e l D ...euvlsymposium.lbl.gov/pdf/2015/Posters/P-RE-04_Shigaki.pdfNissan Chemical, ‐where unique & solution meet 2 0 1 5 I nte

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


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



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.



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.


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.



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)



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.



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



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 :



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.



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.)



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



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.



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



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



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



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.



Acknowledgement

Thank you

Documents

Nissan Chemical, ‐where unique & solution meet Nov e l D ...euvlsymposium.lbl.gov/pdf/2015/Posters/P-RE-04_Shigaki.pdfNissan Chemical, ‐where unique & solution meet 2 0 1 5 I nte