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
Double diffraction version
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.
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.
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)
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.
Sample Holders
Stainless steel vacuum holder for wafer face orientation measurement.
Integrated engraving ensures precise wafer positioning for flat and notch determination.
Models available for wafers up to 300 mm in diameter.
One of the main advantages of the GM series X-ray units lies in their high modularity, allowing the installation of a wide range of accessories such as sample holders, tables, slides, dedicated fixtures, and tooling, in order to adapt the equipment to numerous applications.
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The mechanical design of the system allows these changes to be made without requiring beam realignment, complex mechanical adjustments, or recalibration.
Depending on the type of accessory used, implementation time ranges from a few seconds to a few minutes.
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Samples can be maintained on the different holders:
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either by an adjustable spring pusher
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or by vacuum holding, depending on the application
Although small crystalline sections can be measured with good accuracy (for example wafer flats of 0.3 × 8 mm), the highest measurement reliability is achieved when the crystal face is sufficiently large to be properly and accurately held on the sample holder.
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Further process steps, such as dicing, can be carried out after orientation control, as these operations do not affect the crystal face orientation.
A wide range of standard sample holders is already available for most applications.
When necessary, specific or custom-designed holders can be developed.
​Provides excellent holding for all samples whose dimensions exceed the minimum width of the window.
Compatible with incident and reflected beam angles ranging from approximately 7° to 55°.
Ensures optimal holding for samples whose width exceeds that of the slit.
Used in cases of low incident beam angles.
The reflected beam angle is limited to approximately 55°.
In this configuration, the X-ray beam passes above the holder to reach the maintained crystal face.
Used for all incident and reflected beam angles when other types of holders are not suitable.
Holder for wafer flat orientation measurement.
To use with with vertical window holder.
Holder for small inci- dent angle beams. Must be used for ex.
with LiNbO3, LiTaO3
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.
PC display option (See page 1)
Displays decimal and sexagesimal degrees.
Standard or customized software.
Storage of up to 4 mesurements per sample.
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
Standard holder with vertical window
Commonly used in many applications.
Motor driven rotating holder for wafer orienta- tion measu-rement. PC calculates total plane offset and offset direction
Holder for orientation process of ingot flat.
The ingot holder is used to transfer the ingot orientation to the grinder.
Special tilting holder for measurement of crystals with inclined planes.
In some cases, long window detectors can be used as an alternative.
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.