LIGA uses deep X-ray lithography with synchrotron radiation for the production of high aspect ratio polymer microstructures. By shadow printing an X-ray mask is copied into an X-ray sensitive resist. A chemical developer dissolves the irradiated areas. Free lateral shape, structures heights from several µm up to several millimetres, vertical sidewalls with optical quality (Ra < 20 nm) and sub µm structure details are the basic characteristics of this process step.
The microstructure laboratory at KARA consists of three beamlines for deep x-ray lithography, each dedicated to a specific task in the LIGA-process. In this chapter we present the LIGA2 (Litho2) beamline, dedicated to deep X-ray lithography (DXRL). The typical data for the structural height ranges from 100 to about 2000 microns with a smallest width of 1 to 20 µm. Smaller line widths as well as higher structures are design dependent and therefore under further development.
The whole laboratory is placed inside a clean room for accurate environment conditions. The experimental equipment, together with the microstructure fabrication capabilities at IMT/KIT, is a unique installation for high precision and high aspect ratio microstructure fabrication. Even the resist preparation, development and optional electroforming process is done by using the clean room capabilities and expertise of IMT.
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Energy range
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2.5 - 12.4 keV
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Source
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1.5 T Bending magnet, bending radius: 5.556 m
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Be-window
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225 µm
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Mirror
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Si/200nm Ni @ 4.85 mrad
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Distance: source point-mask plane
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14.73 m
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Distance: source point -mirror
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9,2 m
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Be-window aperture
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20 mm (vertical) x 110 mm (horizontal) |
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Usable horizontal fan
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108 mm
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Sample environment
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100 mbar He
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Experimental setup
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JenOptik DexKfK X-ray scanner with tilting option (+/- 60°)
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Alignment / instrumental overlay accuracy
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External / 2µm
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