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PORTABLE X-RAY
FLUORESCENCE DIFFRACTOMETER / SORTER
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Applications
1. Electronic and
semiconductor industries.
2. Piezo-acoustic
electronics.
3. Quantum
electronics
4. Jewelry.
5.
Assessment of wafer surface treatment quality. |
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Portable X-ray diffractometer/sorter is
designed
to determine the deviation of the wafer shear cut plane from
specified crystallographic plane.
The main element
in the x-ray scheme of this compact diffractometer is the
Kumakhov focusing capillary lens (x-ray optics) with x-ray
convergence angle of ~ 1-3°, allowing, with the help of
linear-coordinate detector with window 25-30 mm, to determine the technological
orientation of wafer cut orientation versus reference
(standard).
 Kumahov's
Lenses in this x-ray diffractometer provide the necessary corners of convergence of
primary beams, providing a kinematical-free shootings series
for monocrystals. Changes of the diffraction corners is made
only at transition to the other monocrystals of the other
structure.
The use of the positon - sensitive detector in this x-ray
diffractometer and an original
design of the holder allow somebody to get needed accuracy
in mesurements of the angle
Δψ.
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X-ray tube block (x-ray tube 1 with collimator system 2) forms
primary divergent beam which is collected by bent (according to
Iohan) monochromator crystal 3 (SiO 2(101.1)) into a
point on a cut surface of analyzed sample 4, which is set in
crystal holder 5. This scheme requires complicated precise
alignment. |
Focusing lens (2) used for x-ray beam formation with a certain
convergence angle α allows not only to largely simplify
the optical scheme of diffractometer used for determination of
crystal planes’ orientation (5)Δψ relatively to a specified
plane orientation but also to improve determination of
Δψ reproduction, to decrease device dimensions and reduce the
x-ray tube power. |
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Requirements to a convergence corner
α of the x-ray beam from a full
Kumahov's lens, is defined as much as possible corner
deviation of orientation crystallography planes
jmax
from the set corner
j
(α> 2
jmax).
The use of the x-ray beam converging on the sample allows to get
rid of rotation a monocrystal plate for the purpose of
maximum diffraction reflexions search . An accuracy definition
of a measured deviation corner is ±5 " |
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The principle of operation
x-ray diffractometer / sorter
is based on fact that the
radiation generated by a x-ray tube, collimated by the
polycapillary lens, is diffracted on a
 crystal
lattice of an irradiated material. Angular distribution of
intensity diffracted radiations is registered by the
linear-co-ordinate detector and processed by digital devices for
the purpose of definition an angular position, intensities
and width at semiheight diffraction peaks, which changes define
a deviation of a corner of a cut of monocrystal plates from
rating value.
The width of diffraction peak in
x-ray diffractometer depends
on quality processing of a monocrystal surface of a wafer.
Therefore simultaneously with identification of orientation of a
wafer, probably also to estimate quality of a surface of
reflexion after processing. |
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The x-ray diffractometer /
sorter is supplied with
software for automatic definition of a corner deviation for
investigated monocrystal wafers.
Special crystal holder allows to analyze wafer orientation of
any forms and sizes, and don't need alignment before mesurements.
The analysis process, from a data
aquesition to its processing, before an acceptation results in
the form of tables angular intensity positions, at
the semiheight diffraction width maxima, is automated and
carried out by personal computer PC. |
Basic technical
characteristics of X-ray diffractometer / sorter
Goniometer weight
– 10kg
Control unit - 15êã
Total weight of the unit
– 25kg
X-ray tube:
consumption –
10(5)W
anode
– Cu
focal spot –
0,2õ2ìì
cooling – air
Detector gas filled,
position-sensitive, proportional
Length of working window – 25 – 50
mm
Special resolution – 115mkm
Consumption power
– 220V, 50-60Hz, 125W |
X-RAY DIFFRACTOMETER / SORTER
CONSISTS:
1
X-ray tube in a
protective housing,
2
combined with collimation
device on the basis of polycapillary lenses;
3.
linear-coordinate sensitive detector;
4. goniometric unit;
5.
samples holder;
5. portable
computer
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also, a power and registration unit , containing the
high-voltage power supply of the x-ray tube and
the linear-coordinate sensitive detector, the analogue-digital
converter, a board of the interface
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