micro- and nano-technology · 2013-05-15 · micro- and nano-technology..... for optics 3.2...

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

U.D. U.D. ZeitnerZeitnerFraunhofer Institut fFraunhofer Institut füür Angewandte Optik und Feinmechanikr Angewandte Optik und Feinmechanik

JenaJena

Micro- and Nano-Technology...... for Optics

3.2 Lithography

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

“Printing on Stones”

Map of Munich

Stone Print

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Contact Printing

resist

substrate

light

mask

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Mask Aligner

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Mask Aligner

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Mercury Emission Spectrume - lineghi

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Proximity Printing

resist

substrate

light

mask

proximity gap

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Projection Lithography

resist

substrate

light

mask

projection optics

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

The inverse microscope

microscope lithography

microscope lens projection lens

imageobject

image object

light source

light source

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Photolithography Examples

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

ASML-Stepper

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Zeiss SMT, WO 2003/075049

… for DUV-Lithography

Stepper Objective …

…aspheric lenses

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Double Patterning

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Principle ofhalf tone masks

Principle ofgray tone masks

brightness in the wafer plane

0

1

2

-1

-2grating period or pitch > λ

0

1

2

-1

-2

0

1

2

-1

-2

0 0 0

grating period ore pitch < λ

small medium highfilling factor:

blocking of higher orders by a lens

- Sub wavelength masks- HEBS glass masks- LDW glass masks

higher orders do not exist

Physics of Half-Tone- and Gray-Tone-Masks

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

half tone mask

objective

gray tone image

pulse densitypulse width

type of masks

+1-1

Courtesy of K. Reimer, ISIT/FhG

Also possible:

- combinations

- Error diffusion

Half-Tone Lithography

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Holography Examples

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

12

3 4

5

67special features:

• adjustable angle of incidence: 0deg- 55deg ( ±1deg ) • low divergence: 0.1deg• interference filter: 313nm, 365nm, 435nm

1234567

mercury lampcollimatorpolarizerinterference filtercold-light mirrormasksubstrate

Mask Aligner With Collimated Illumination

12

3 4

5

67

oblique incidence

normal incidence Suss MA6-NFH

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

h

ϕL

-1st0thϕ0ϕ-1

d b

Two beam interference Symmetricdiffraction angles

only 0th and -1st order→ wavelength

dd

23

2 << λ

Littrow - mounting→ angle of incidence

dL 2sin

λϕ =

Parameters:• Wavelength λ / Pitch d • Angle of incidence ϕ• Groove depth h

Duty cycle f = b / d

rigorous calculations→ duty cycle and

groove depth of themask grating

Equal intensities

Mask

ResistSubstrate

Principle of Pattern Transfer

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Experimental Results

1 µm

1 µm

Mask

Copy

Phase mask Amplitude mask

1 µm

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

λ/2 < p < 3λ/2 λ/2 < p < λ

pmp

p p=pm/2

Incidence Angle

� also usable for gratings with different orientations (e.g. circular gratings)

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Laser Lithography

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

Laser Lithography – Scanning Beam

scanwidth

AOD

U~ deflection angle

substrate motion

AOM

U~ profile

mirror

focusing lens

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

DWL 400-FF Laser Writer

HIMT

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

basis system: DWL 400, Heidelberg InstrumentsLaser: He-Cd, λ=442nmmax. writing field: 200mm x 200mmmin. spot size: ∼1µmautofocus system: opticalwriting mode: variable dose (max. 64 level)

spot positioning by stage movement andbeam deflectionlateral scan (width up to 200µm at max. resolution)

writing speed: 10 – 20 mm²/min on planar substrates(depending on structure)

writing on curved substrates:substrate table: cardanic mount, tilt in two orthogonal axesmin. radius of curvature: ∼10mmmax. surface tilt angle: <10°max. sag: 30mm

DWL 400-FF Laser Writer

INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena

variable dose exposure:

development:

resist

substrate

intensity modulatedexposure beam

t1 t2x

y

e-beam,laser beam

writing pathsubstratemovement

• dose dependent profile depth after development process• high flexibility for arbitrary surface profiles

Lithography with variable dose exposure