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