fabrication of grid mask and test requirements of fiducial mark fabrication of sample mask test...
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Fabrication of Grid Mask and Fabrication of Grid Mask and Test Test
Requirements of fiducial mark
Fabrication of sample mask
Test by beam exposure (X-ray & UV)
Summary
S. H. Kim and J. S. SongGyeongsang National UniversityKorea
Mark size : up to 0.1 m (grain size)
Gap of each mark : 100 m
in a changeable sheet (12.5 ×10 cm2)
Requirements of fiducial mark
m
m
Diameter 0.1 m Fiducial Mark
Size of mask : 15x15cm2
Area of hole marks : 15 x 7.5cm2
(half below)
Base : Quartz crystal (3.2mm thick)
Coated material : Chrome (10 m thick)
Gap distance of each marks :
x: 99.6 m, x: 99.3 m
Hole size : 0.89 m
Fabrication of samlple mask
Exposure by UV beam
Mounter
Unit : mm
by ×20 obj. lens
by ×20 obj. lens
Exposure time : 1 sec
UV wave length : 255 nm
Distance from source to trget : 30cm
Mask holes Exposed image in X-ray film
Diffractive effect by UV beam
A B C
Film
Chrome Mask
A
BC
Unit : m
Spacer
Hole size: ~4 mGap distance: ~100 m
B
by ×20 obj. lens
Exposure time : 15 sec
UV wave length : 350 nm
Exposed image in the emulsion
by ×50 obj. lens
Hole size: ~5 mGap distance: ~98 m
X-ray beam in GSNU Hospital
Energy: 40 kVp(General), 23 kVp(Mamography), 60 kVp (Dental)
Target: X-ray film and litho film(Low sensitivity)
We could not get hole images!
Exposure by X-ray beam
Summary
We need more test by two beams, especially a few keV X-ray.
In case of UV beam, we have to get best conditions :
- beam energy
- exposure time
- need to use parallel beam