review* of metallic resists for euv · euv symposium 6/16 brainard and brainard 1 review* of...

EUV Symposium 6/16

Brainard and Brainard 1

Review* of Metallic Resists for EUVRobert Brainarda and Lisa Brainardb

a. Colleges of Nanoscale Science and Engineering; SUNY Polytechnic Institute

b. Sage College

[email protected]

I. Metal-Oxo Films (OSU/Inpria)

II. HfOx and ZrOx Nanoparticles (Cornell)

III. Molecular Organometallic Resists for EUV (MORE)

(SUNY Poly and New Paltz)

A. Tin Oxo Clusters (Cardineau)

B. Tin Carboxylates (Del Re)

C. Transition Metal Oxalates (Freedman)

D. Positive-Tone Palladium (Sortland)

E. High-Speed Main-Group Olefins (Passarelli)

IV. Acknowledgements

*For 2nd Edition:

mailto:[email protected]

EUV Symposium 6/16


Optical Density Map of the Elements

Positive Tone

Super-Fast

Super-Low LER

Cardineau & Brainard MicElec 127 (2014) 44

Tin-Oxo

ClusterNegative Tone

Inpria

HafSOx

Super-Fast

Nanoparticles

Inpria

SnOx

EUV Symposium 6/16


A B

I. Metal-Oxo Films (OSU/Inpria)First Publication of EUV Results. BMET SPIE 2010

Naulleau & Anderson SPIE 2010 76361J1

EUV Symposium 6/16


(1)

(2)

I. Metal-Oxo Films (OSU/Inpria)Published Photoreactivity

The key to the photoreactivity of the HafSOx resists appears to be controlling

the dehydration reaction (eq 1) which crosslinks and thereby reduces the

solubility of these metal oxo-films. Dehydration is prevented by binding peroxide

to Hf. Fortunately, the metal peroxide decomposition can be induced by high-

energy light or electrons (eq 2) thereby creating metal hydroxides that can

condense and become insoluble.

In brief, the metal peroxides allow the resists to dissolve in the unexposed

regions and upon photolysis the metal peroxides become metal hydroxides and

condense to become insoluble features of the negative-tone resists.

Amador & Keszler SPIE 2014 90511A

EUV Symposium 6/16


A

B

I. Metal-Oxo Films (OSU/Inpria)Imaging at PSI (2014)

Ekinci & Vockenhuber SPIE 2014 904804

EUV Symposium 6/16


A B

I. Metal-Oxo Films (OSU/Inpria)Imaging at PSI (2014)

Ekinci & Vockenhuber SPIE 2014 904804

EUV Symposium 6/16


II. HfOx and ZrOx Nanoparticles (Cornell)

Many versions of these resists were prepared using methacrylate as a ligand

and formulated with either photoacid generators or free-radical initiators, suggesting

that the negative-tone imaging mechanisms might involve free-radical crosslinking.

However, careful studies revealed that

the negative-tone solubility switches do not

involve free-radical crosslinking, but

instead involves a ligand exchange

mechanism that can proceed without PAGs

or with the assistance of PAGs.

Size distribution

of nanoparticle

suspensions

Krysak & Ober SPIE 2014 904805-5

Trikeriotis SPIE 2010 76390E2

EUV Symposium 6/16


II. HfOx and ZrOx Nanoparticles (Cornell)These nanoparticle resists are capable of good EUV patterning capability at extremely fast

photospeeds. 20 and 30 nm isolated lines were printed using doses of 2.4 and 1.6 mJ/cm2.

Although the LER values of these resists are modest (5-7 nm), the LER is not too poor

considering that the resists are extremely sensitive and are composed of nanoparticles that are

1-2 nm in diameter.

Jiang & Ober JPST 2014 27, 663

HfO

2D

MA

ZrO

2D

MA

2.4

mJ/c

m2

1.6

mJ/c

m2

EUV Symposium 6/16


III. MORE: A. Tin Oxo Clusters (Cardineau)

(X) (R)

Em

ax

The resist sensitivity shows

good correlation with anion size.


[(PhSn)12O14(OH)6]Cl2

Dose: 350 mJ/cm2

Resolution: 18 mJ/cm2nm

EUV Symposium 6/16


4.9 560 4.5 520 2.9 380 5.6 380 8.9 350

LER (nm) Dose (mJ/cm2)

9.4 560 6.2 520 7.7 380 8.1 380 13 350

3.9 500 3.6 480 3.8 350 5.5 350 14 320

3.9 560 3.6 520 3.8 380 5.5 760 14 700

7.3 560 9.0 520 7.6 380 9.0 380

3.0 560 2.5 520

Resolution

Capabilities

for Various

Anions.

1822253550h/p CD (nm)

X


EUV Symposium 6/16


II. MORE: B. Low LER Tin Resists (Del Re)

50 nm

50

43

600

600

300

300 410

360

35 nm

2000 RPM 4000 RPM

1.6

1.4

1.9

2.28.1

8.9 1.2

1.1

Dose (mJ/cm2) LER (nm)

1.9

LWR (nm)

13

8.9 1.7

1.7

3.21.9

2.9

Del Re & Brainard JM3 2015 043506

EUV Symposium 6/16


0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

20304050

Ro

ug

hn

ess (

nm

)

Feature Size (nm)

II. MORE: B. Low LER Tin Resists (Del Re)LER Does Not Follow Z Parameter

Dose = 300 mJ/cm2

Theoretical LWR and LER

Measured

LWR and LER

CD: 35 nm 35 nm

LER: 1.4 nm 1.1 nm

LWR: 1.9 nm 1.7 nm

Del Re & Brainard JM3 2015 043506

EUV Symposium 6/16


18 nm

30 mJ/cm2

Freedman & Brainard SPIE 2014

III. MORE: C. Transition Metal Oxalates(Freedman)

EUV Symposium 6/16


III. MORE: C. Transition Metal Oxalates(Freedman)

0

10

20

30

40

50

0 10 20

Th

ickne

ss (

nm

)

Energy/area (mJ/cm2)

Emax =

8 mJ/cm2

Emax = 35

mJ/cm2Emax =

4 mJ/cm2

0

10

20

30

40

50

60

0 25 50 75 100

Th

ickn

ess (

nm

)


0

10

20

30

40

50

60

0 10 20T

hic

kin

ess (

nm

)


Esize

Freedman & Brainard SPIE 2014

EUV Symposium 6/16


III. MORE: D. Positive-Tone Palladium Resists

(Sortland)

Sortland & Brainard JM3 2015 043511

22 nm 30 nm

Esize = 50 mJ/cm2

EUV Symposium 6/16


Excellent sensitivity at modest resolution.

III. MORE: E. High-Speed Main-Group Olefins (Passarelli)

JP-20:

hn or e-

JP-20

Initiation: Propagation:

R = metal or carboxylate

centered radicals

…

Exposed region crosslinked:

less soluble in developer

50 nm 35 nm 25 nm

Dose = 5.6 mJ/cm2

Proposed mechanism is based on photo-initiated free radical polymerization.

Weaker Bond

Polymerizable

Olefin

Passarelli & Brainard JM3 2015 043503

EUV Symposium 6/16



M = Sb, Bi, Sn or Te

R = Aliphatic or Aromatic Sb - C Group

O2CR’ = Carboxylate Group

JP-20:


EUV Symposium 6/16


Sensitivity Hypothesis: The ratio of polymerizable olefins to space filling R groups

is the largest contributor to sensitivity characteristics of antimony acrylate resists.


Unexpected Result: Changing Sb-R bond did not dramatically affect sensitivity.

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0 2 4 6 8 10

Rela

tive

Th

ick

ne

ss

Dose (mJ/cm2)

R = Phenyl Cyclohexyl

Emax

‘’

5.6 5.650 nm 35 nm

5.0 5.050 nm 30 nm

Aliphatic

R = Cyclohexyl

Aromatic

R = Phenyl

Dose (mJ/cm2)


EUV Symposium 6/16


0.5

5

50

3 4 5 6 7 8 9Polymerizable Olefin Loading (%)

Em

ax

(m

J/c

m2)

R =

R =

R =

R =

R =

R =

R =


Carboxylate Group:

=

=

=

Y = 2000e-x

R2 = 0.91


EUV Symposium 6/16


Acknowledgements

Project Funding By:

PSI:

Michaela

Vockenhuber

Yasin Ekinci

BMET:

Chris Anderson

Group Members:

James Passarelli

Ryan Del Re

Miriam Sortland

Michael Murphy

Jodi Hotalen

Levi Dousharm

Brian Cardineau

Daniel A. Freedman

Mark Neisser

Chandra Sarma

Steve Putna

James Blackwell

Andrew Grenville

Stephen Meyer

review* of metallic resists for euv · euv symposium 6/16 brainard and brainard 1 review* of...

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