St Gobain Crystals and Detectors manufacture Gallium based Garnet Crystals by the Czochralski process, with a high level of crystalline perfection, using computerized pulling machines.
A proprietary process of double side polishing has been developed and allows us to offer polished wafers that exhibit very good flatness and surface quality.
We offer Gadolinium Gallium Garnet (GGG) & Substituted Gadolinium Gallium Garnet (SGGG).
| | GGG | SGGG |
| Lattice parameters (at 20oC) |
A |
12.383 ± 0.001 |
12.497 ± 0.003 |
| Diameter |
mm |
Up to 100 ± 0.13 |
457 ± 51 |
| Thickness |
µm |
457 ± 51 |
457 ± 51 |
| Orientation Polished surface |
|
(111) ± 0.1o |
(111) ± 0.1o |
| Orientation Reference flats |
|
Perpendicular to ( 1 1 2 ) and ( 1 1 0 ) ± 2o |
Perpendicular to ( 1 1 2 ) and ( 1 1 0 ) ± 2o |
| Flatness |
µm |
Less that 6µm over 80% of the central area |
Less that 6µm over 80% of the central area |
| Total defect density |
cm-2 |
<1 |
<10 |
Special orientations like (100) and (110) may be supplied on request.
Other thicknesses are available on request.
Standard polished substrates are core and facet free. Wafer edges are rounded by bevelling and polishing.
Dislocation density measurements are made by visual inspection after a chemical etching process.
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