- X-ray fluorescence microprobe beamline
The physics design
of the beamline is over. Ray tracing and heat load calculations have been
performed.
This beamline has
been designed with our aim to do normal XRF and micro mapping of sample. The
following are the photon beam parameters on the sample. The beamline has
energy range 4-20 keV. The energy resolution expected is 10,000. The beam size
at the sample is 4microns X 8microns. Photon flux at the target is expected to
be in the range 107-108 photons/sec. Optical layout is
shown in figure 6.
Figure 6: Optical Layout of X-Ray Fluorescence Beamline
This beamline can also be operated in various
modes like focused (microprobe) , high energy resolution probe, normal XRF
mode and TRXRF mode.
- Soft and Deep X-ray Lithography (SDXRL)
Beamline on Indus-2
Detail optical design of
soft and deep X-ray lithography beamline on Indus-2 has been carried out .
Optical layout of the SDXRL beamline is shown in Figure 7. The beamline
optical elements consist of a plane mirror and a torroidal mirror. The angle
of incidence on these mirrors in combination with the filters defines the
energy window. The horizontal and vertical acceptances of the beamline are 5
mrad and 1 mrad respectively. Beamline performance is optimized on the
following parameters; runout error (<
±
2.1 mrad), penumbral blur (<
±
0.8 mrad), power delivered at wafer location, beam size at sample/mask (55 (H)
x 2 (V) mm2) and horizontal intensity uniformity (<
±3%).
The beamline can also operate in no optics mode, with mirrors moved out of the
beam path.
Aerial image formed at mask-wafer stage, by the
beamline configuration (with mirror(s) angle
q1 = 1.70
and q2
= 1.750) is shown in Figure 8. Beam size is enlarged at
mask-wafer stage by scanning X-ray stepper/scanner in vertical direction.
Considering beamline acceptance and performance, mirror sizes are limited to
100 mm (width) and 750mm (length). Surface roughness values of
3Å, 5Å and 10Å for mirrors are used to study its effect on image
at the mask-wafer stage. Effect of slope errors (0 to 271mrad)
in meridional plane, on beam image is simulated. Torroidal mirror
misalignments (0-1000 mm in translation and 0 to 207 seconds in rotation) and
their effects
on beam shape and size
are simulated.
Figure 7: Optical design of SDXRL beamline on Indus-2
