Nickel LIGA (fully anchored structures) (PMMA): View

on front Nickel LIGA (fully anchored structures) (PMMA)

on front

1 Titanium E-beam evaporation

Material	titanium

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2 Gold E-beam evaporation

Material	gold

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3 Titanium DC sputtering

Material	titanium

4 Titanium surface treatment

Depth	100 nm	Material	titanium

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5 X-ray photolithography (front-front align) (PMMA)

5.1 PMMA resist sheet bonding

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5.2 Surface fly-cutting

Material	photoresist (category)

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5.3 X-ray front-front align

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5.4 X-ray exposure

Material	PMMA

5.5 Photoresist develop (PMMA)

Material	PMMA

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6 Plating preparation (descum)

Material	SU-8

7 Titanium wet etch

Material	titanium

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8 Nickel electroplating (sulfamate)

Material	nickel

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9 X-ray flood exposure w/o mask (PMMA)

Material	PMMA

10 Photoresist develop (PMMA)

Material	PMMA

11 Titanium wet etch

Material	titanium

12 Gold wet etch

Material	gold

13 Titanium wet etch

Material	titanium

Process characteristics:

Nickel thickness

0 .. 500 µm

Resist thickness

0 .. 1000 µm

Gold thickness

0.1 µm

Mold deviation across height

2 µm

Mold height uniformity

10 µm

Mold sidewall roughness

200 nm

Release layer thickness

1 µm

Smallest feature size

5 µm

Titanium thickness

0.01 µm

Wafer size

Comments:

This LIGA process is used to
make structures that are
completely attached to the
substrate.
Application example: Miniature
electrode arrays.
Pricing available upon request.
Process requires an X-ray
mask. Please refer to
'Mask-making' section.
Process is confined to a 2"
diameter area.