GM Series
The GM Series X-ray measurement systems are general purpose heavy duty production units especially designed for measuring the orientation of crystal products with respect to a selected crystallographic plane. Orientation processes of small to medium size crystals can be performed with the help of dedicated holders and jigs.
All single crystal can be processed, for all applications such as semi conductors, opto-electronics, optics, etc..
Applications
â– Orientation measurements
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Crystal face (Wafer, blank, block, bar, etc..). Depending of sample size, dedicated holder(s) may be required.
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Ingot flat
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Wafer flat and wafer notch (optional holder)
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Seed axis of round or square seeds (optional holder)
â– Orientation processes
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Flat orientation on medium size OD ground ingots
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Crystal face, with specific adjustable holders.
Digital angle display
â– Display options
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Decimal : resolution 0.01° - 0.001°
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Degrees, minutes, seconds : 1 or 5 seconds
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PC and software : decimal and deg. min. sec. Any resolution. Simultaneous display of absolute and relative angle values (delta theta). Standard or
customized software. Storage of various data.
All display versions enable reset to zero at any position. Automatic delta-theta reset for each crystal plane. Automatic recalibration at start-up or at any time.
Versions and configurations
â– Capacities
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for loads up to 10 kg
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for loads up to 25 kg
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special versions for loads up to 100 kg
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Custom made versions
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Dual-station, including mixed versions with a station of GM.SI or GM.WS series.
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Dedicated holders for all applications
â– Double diffraction option
The GM series goniometers are available either for single diffraction operation, which is sufficient for most applications relating to semiconductors, or in double diffraction configuration with an incident beam monochromator.
The standard monochromator is a Quartz crystal with plane (01-1).
Different configurations with other crystals such as Lif, Si, Ge, etc.. can also be supplied.
Range of operation
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Goniometer rotation range : <0 to approx. 70°, with fast/coarse and slow/fine rotation control over the whole rotation range.
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Detector setting range : <0 to approx 110°. Detector ca be indexed at several dedicated positions (option).
Performance (Single diffraction)
Double diffraction version
In a single diffraction goniometer, the sharpness of the reflection peak depends mainly on the beam divergence, which comes out of the collimator. Even in the very best conditions, it is not possible to get a reflection peak enabling a measuring accuracy better than ± 10 to15 seconds.
With the double diffraction configuration a first crystal ’’monochromator" is mounted directly on the path of the incident X-ray beam. This allows the beam to be made parallel by Bragg reflection on a family of reticular planes. Its divergence in this case is only of a few seconds of arc. After reflection on most samples, it becomes monochromatic resulting in an extremely sharp reflection peak. Our unique electronics with "peak amplifier" enables its detection with an accuracy of 1 to 2" of arc.
Versions and configurations
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Output voltage : 30 kV – DC
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Maximum rating : 30 mA
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X-ray tube : copper target, water cooled. Other targets
on request.
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Apparent focus : linear fine focus. Spot focus when required.
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Mains : 220 V 50/60 Hz, 1-phase, 10 A
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Water supply : 2.5 bar. Flow rate 3.5 l/min
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Measurement accuracy : ± 0.005° to ± 0.02°, depending (in particular) of crystal type, plane and surface condition.
Performance (Double diffraction)
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Measurement accuracy : ± 2 seconds to ± 15 seconds depending of crystal type, plane and surface condition.
Examples : Quartz (01-1) ± 1 sec repeated over 20 measurements.
Quartz (02-3) ± 2 sec/30 measurements.
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Measuring tests can be made on customer's samples.
Detection Unit
Proportional counter linked to a special integrator with peak amplifier, giving a high detection accuracy.
Optional long window detectors for detection of a beam reflected by strongly tilted planes (crystal plane is inclined, not parallel to goniometer axis).
Voltage is adjustable from 1000 to 1850 V.
Voltmeter and adjustment potentiometer are located in the casing facing the operator.
Stainless steel vacuum holder for wafer face orientation measurement. Engraving for accurate positionning of the wafer for flat and notch.
Models for wafer up to 300 mm diameter.
Specimen holders
One of the greatest advantages of the GM series X-ray units is the capability which is offered to install an infinite number of attachments such as specimen holders, tables, slides, jigs and other fixtures in order to use the equipment for different applications.
Besides, the mechanical concept of the unit enables such changes without the need of any beam re-alignment, mechanical setting or calibration. Depending of the attachment, time involved for this operation ranges from a few seconds to a few minutes.
The sample can be maintained on all types of holders either by an adjustable spring pusher or by vacuum.
Although small crystal sections can still be measured with good accuracy (for ex. wafer flats of 0.3 x 8 mm) the best measurement reliability is ensured when the crystal face is sufficiently large for being properly and accurately hold on the specimen holder. Further process steps such as dicing can be made after orientation check, since such process does not affect the crystal face orientation.
A large number of specimen holders is already available for all kind of applications. When needed, customized models can be offered.
​Horiz. window type. Provides excellent holding for all samples which are larger than the narrowest part of the window. Incident and reflected beam angles from 7° to ca. 55°.
Double resting surface.
Provides excellent holding for samples larger than the width of the slit. Used in case of small incident beam angles. Reflected beam angle limited to ca. 55°
Overhanging configuration. The beam passes over the holder to reach the crystal maintained on its face. Used for all incident and reflected beam angles, when other holders are not suitable.
Holder for wafer flat orientation measurement.
To use with with vertical window holder.
Standard holder with vertical window
Commonly used in many applications.
Holder for small inci- dent angle beams. Must be used for ex.
with LiNbO3, LiTaO3
Motor driven rotating holder for wafer orienta- tion measu-rement. PC calculates total plane offset and offset direction
Holder for seed orientation measurement. Instantly mounts on the goniometer table.
Holder for wafer flat and notch orientation measurement.
Wafer diameter from 100 to 300 mm.
Holder for orientation process of ingot flat.
The ingot holder is used to transfer the ingot orientation to the grinder.
PC display option (See page 1)
Displays decimal and sexagesimal degrees.
Standard or customized software.
Storage of up to 4 mesurements per sample.
Special tilting holder for measurement of crystals with inclined planes.
In some cases, long window detectors can be used as an alternative.
Safeties and protections
The equipment has been designed to offer both maximum protection and easy operation.
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Electromagnetic rotary shutter controlled by a non latching foot switch.
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Shutter interlock switch actuated by the sample in measuring position
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Green / Red control lights : indication of shutter status.
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"X-ray ON" light with automatic equipment shut-off in case of lamp failure.
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Shields and screens stop direct or scattered radiation
Customized equipment
Despite of the large variety of equipment and accessories offered, the equipment must often be customized in order to fulfill the user's requirements, particularly with respect to the size and shape of samples. This catalog does not show all available holders.
If the samples to be measured cannot be properly hold by the standard holders mentioned in this catalog, or already supplied for similar applications, we can still offer specific solutions.
This can be the case for instance when the samples to measure are smaller than the X-ray beam aperture of the sample holder fitted to the goniometer.
For any such application, consult us.
Delta technologies permanently improves his products.
Equipment may differ from the data mentioned in this non contractual document.