Portable X-ray diffractometer / sorter on the basis of Kumakhov focusing x-ray lens (capillary optics)

Up-to-date Portable X-ray Diffractometer for Single Crystal Quality Control

Miniature

Easy alignment and sample change

Radiation safety

High accuracy of determining angle of deviation - 5"

No rotation parts

Fast wafer sorting

Applications

1. Electronic and semiconductor industries.

2. Piezo-acoustic electronics.

3. Quantum electronics

4. Jewelry.

5. Assessment of wafer surface treatment quality.

X-ray Diffractometer / sorter is designed

to determine the deviation of the wafer shear cut plane from specified crystallographic plane

The main element of the x-ray diffractometer in the x-ray scheme of this compact x-ray 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, to determine the technological orientation of wafer cut orientation versus reference (standard).

Kumahov's Lenses 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.

Requirements to a convergence corner α of 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 in this x-ray diffractometer 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 ".

The use of a full focusing lens (2) for formation the x-ray beam, with a certain corner of convergence α of X-rays, allows not only considerably simplify the optical scheme of the diffractometer for definition of a deviation of a corner orientation crystallography planes of a monocrystal (5) Δψ from the set corner, but also considerably to improve reproducibility of definition Δψ, to reduce dimensions of the device and capacity of a x-ray tube (1).

The principle of operation

The X-ray diffractometer 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 depends in this diffractometer 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.

The X-ray diffractometer is supplied with software for automatic definition of a corner deviation for investigated monocrystal wafers.

The analysis process in this x-ray diffractometer, 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.

TECHNICAL CHARACTERISTICS

Range of measured cut angles	от 0^o до 35^o
Range of measured diffraction angles 2q	от 20^o до 130^o
Maximum allowed basic absolute error of angular positions measurements for single crystal diffraction maximums and cut angles	±0.0014^о
Root-mean-square deviation of single crystal diffraction maximum position measurement	0.001^о
Maximum allowed complementary error of measurement of diffraction maximum angular positions and cut angles in case of ±10 % voltage fluctuation compared to nominal	±0.001^о
Maximum allowed complementary error of measurement of single crystal diffraction maximum positions and cut angles in case of temperature fluctuation within the range (+10 … +30)о С per each 10^oС.	±0.001^о
Rise time, min.	30
Mean time between failures, not less, hrs	3000
Power consumption, not more, VA	150
Supply voltage, V Frequency, Hz	220±22 50 ±1
Weight, not more, kg	60
Dimensions (length х width х height), mm - goniometric unit - power and registration unit	700 х 600 х 400 600 х 300 х 480
X-ray tube: power anode focus size cooling	10(5) W Cu 0,2х2mm air
Detector Working window length Spatial resolution	gas filled, position-sensitive, proportional 25 – 50 mm 115 mm

THE X-RAY DIFFRACTOMETER CONSISTS FROM:

X-ray tube in a protective housing,
combined with collimation device on the basis of polycapillary lenses;
linear-coordinate sensitive detector;
goniometric unit;
holder for samples

And 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, and the portable computer