Microfabrication technologies
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

Microfabrication Technologies PowerPoint PPT Presentation


  • 60 Views
  • Uploaded on
  • Presentation posted in: General

Microfabrication Technologies. Luiz Otávio Saraiva Ferreira LNLS [email protected] OUTLINE. Lithography Transfer of Patterns Bulk Silicon Micromachinning Surface Micromachinning LIGA technique. Litography - Evolution. France, 1822 Graphic arts. Printed circuit board- 1940-1945.

Download Presentation

Microfabrication Technologies

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Microfabrication technologies

Microfabrication Technologies

Luiz Otávio Saraiva Ferreira

LNLS

[email protected]


Outline

OUTLINE

  • Lithography

  • Transfer of Patterns

  • Bulk Silicon Micromachinning

  • Surface Micromachinning

  • LIGA technique


Litography evolution

Litography - Evolution

  • France, 1822

  • Graphic arts.

  • Printed circuit board- 1940-1945.

    • 0.1mm wide lines.

    • (It may be used for microfluidics).

  • Integrated circuit - 1961.

    • 5um wide lines.

  • Wide evolution on electronics industry.

  • Microsystems require progress on 3D lithography.


Lithographic masks

Lithographic Masks

  • Stencil

UV LIGHT

1:1 IMAGE

GLASS OR QUARTZ

LIGHT ABSORBER

(800A Cr)

PHOTORESIST

SUBSTRATE

  • Light Field

  • Dark Field


Photoresist processing

Photoresist processing

  • Spinning

  • Most used substrate: Si/SiO2

  • Si Oxidation

    • Wet or dry.

    • Between 900 and 1150oC.

  • SiO2 masks the substrate in the following processing steps.

PHOTORESIST

SiO2

Si SUBSTRATE


Transfer of patterns

Transfer of Patterns

Photoresist

SiO2

Si

1

2

Radiation

Unexposed Photoresist

Glass

Metal

4

3

5

6


Mask aligner

Mask Aligner

Karl Suss MA4


3d lithography techniques

Ultra Violet or X-Ray Source

3D LithographyTechniques

Mask

Before Exposure

Exposure

After Development

Thornell & Johansson, J. Micromech. Microeng. (1998) 251-262


Bulk silicon micromachining

ANISOTROPIC

ISOTROPIC

Bulk Silicon Micromachining

A

B

Isotropic

Selective

Anisotropic

Sci. Am. April 1983 pp. 39

Wet or Dry Etch


Back and front side bulk micromachining

Back and Front Side Bulk Micromachining

Suspensedevices

Membrane

Back Side Etch

Cantilever

Front Side Etch


Problems of bulk micromachining

Problems of Bulk Micromachining


Corner compensation

Corner Compensation

No compensation

Beginning etch

Mid etch

End of etch


Surface micromachining

Surface Micromachining

Etch

Before etch

Bridge

Cantilever

After etch


Example of surface micromachining

Example of Surface Micromachining

Sandia


Liga technology

LIGA Technology

Germany - 80’s

Mold Insert

Synchrotron Radiation

Mold Material

Mask membrane

Absorber structure

PLASTIC MOLDING

Resist

Plastic Structure

(Lost Mold)

Base Plate

DEMOLDING

IRRADIATION

Ceramic Slurry

Resist structure

Base Plate

DEVELOPMENT

Plastic Structure

(Lost Mold)

Metal

SLURRY CASTING

Resist Structure

Ceramic Micro-structure

Base Plate

ELECTROFORMING

Mold Insert

FIRING

Metal

Mold Cavity

Plastic Structure

MOLD FABRICATION

Mold Insert

Gate Plate

ELECTROFORMING

Mold Material

Injection Hole

Gate Plate

Metallic Micro-structure

MOLD FILLING

Injection Hole

Plastic Microstructure

FINISHING

DEMOLDING

15


Deep x ray lithography

Deep X-ray Lithography

X-Ray

Be Filter (125um)

Al Filter

Kapton mask Plating Base (0.2um Au)

Au absorber (1.8um)

20um SU-8

100um thick SU-8 film

Si substrate

5 - 15 keV spectrum after filtering

16


Resists for deep x ray lithography

Resists for deep X-ray Lithography

  • PMMA (polymethylmetacrylate)

    • the most used.

    • High resolution.

    • Low sensitivity (2.5 kJ/cm3 minimum dose).

    • Long exposure times.

    • Up to 100µm thick  1-3 keV energy.

    • From 100µm to 500µm thick  3 - 7 keV energy.

  • SU-8 (epoxy based)

    • a promising material

    • Good resolution.

    • High sensitivity.

    • Short exposure times.

    • Difficult processing.

17


Kapton mask

Kapton Mask

20µm thick UV-LIGA process.

Deep UV lithography on SU-8.

Au platting.

2µm Au

20µm SU-8

Plating Base

25µm thick Kapton Membrane

Frame

18


Deep uv lithography deep x ray lithography

Deep UV lithography  Deep X-ray lithography

  • UV

    • Cheap

    • Non-vertical sidewalls - border diffraction effect.

  • RX

    • Expensive

    • Vertical sidewalls - negligible border diffraction.

19


  • Login