Precision grating structures
Polymer structures to be electrated, with a period of 10 µm, thickness of 200 µm, apsect ratio of 40. Mould structures of high aspect ratio X-ray gratings for Talbot interforometry.
■ X-ray gratings for Talbot interferometry

Synchrotron radiation source KARA at KIT
Second generation synchrotron facility KARA is located in the KIT Campus Nord and was formerly called ANKA. It has three beam lines for LIGA micro fabrication and is also equipped with X-ray imaging and X-ray microscopy beam lines and laboratories.

1. X-ray mask fabrication
At first an X-ray mask is made with resist drawn with e-beam or laser, followed by gold electroplating as X-ray absorber. For high contrast structures, an additional high contrast mask is required.

2. X-ray lithography (Lithographie)
Precision structures drawn on the X-ray mask above are copied on the resist on the substrate. Thanks to parallel X-ray beam provided by the synchrotron radiation facility KARA (formerly ANKA), high aspect ratio with smooth side walls are realised.

3. Electroplating (Galvanoformung)
Metal parts with high precision structures with a high aspect ratio are realised with electroplating done between the precision resist gaps made with X-ray lithography.

4. Polymer moulding (Abformung)
To copy the precision structures on polymer substrates, mould inserts for injection moulding and hot-embossing could be made using the process above. This allows for realising precisely replicated micro polymer structures.

High contrast resolution targets for X-ray imaging
With a minimum line width of 0.3 µm and a thickness of more than 3.0 µm in gold, the targets will surely contribute to the improvement of imaging qualities of indsurtrial X-ray detection systems.
Details in press release

Gold coded aperture
- Scale bar: 150 µm
- Minimum line width 6 µm with metal thickness 25 µm
- Other example: Minimum line width 20 µm with metal thickness 400 µm
- Freestanding structure without substrate or polymer resist can be arranged with only minor modifications
- Application example: X-ray source mapping
- Manufacturer: microworks GmbH

X-ray gratings for Talbot interferometry
High aspect ratio absorption gratings, narrow period phase gratings / absorption gratings for a multi-modal X-ray contrast imaging method called the Talbot interferometer.
■ X-ray gratings

X-ray focusing Compound refractive lens, CRL
(Compound refractive lenses (CRLs) used at e.g. SPring-8 to focus monochromatic hard X-ray down to a submicron focus spot size.
■ X-ray lenses

Multi through-holes (X-ray multi-collimator)
Multiple through-holes with a diameter of e.g. 3.0 µm on gold membrane (thickness 80 µm).
Application: X-ray multi-collimator for space science.

Micro through-hole (X-ray aperture)
High aspect ratio through-hole with a diameter of 5 µm in the centre of 200 µm thick gold plate.
Application: X-ray aperture at a synchrotron radiation beam line

Micro gears 1
Application: watch gears
Micro metal structures made with X-ray lithography followed by electroplating. High precision aperture structures in gold and Nickel.
Scale bar (yellow line): 1 mm

Micro gears 2
Application: High precision micro-manipulators
Harmonic drive gear train
- High transmission ratio
- No backlash

High aspect ratio through-holes in nickel
Application: Apertures for hyperspectral camera
- 2.5 µm gap, structure depth 180 µm
- Reduction of keystone and smile
Reference: A Fridman et al. Optics Express 23(10):13659, 2015

X-ray test apertures
Application: Knife edge measurement of synchrotron X-ray beam
Structures: Gold membrane of 30 µm thickness with various square apertures (5 to 1,000 µm side lengths)