Germanium substrates

With more than 40 years of experience in germanium crystal pulling, our facility in Olen, Belgium is one of the few in the world capable of pulling dislocation-free germanium ingots. Diameters range from 4" to 12” (100 – 300mm).

Thanks to the closely-matching thermal and crystallographic properties of germanium and gallium arsenide, epi-ready germanium substrates provide an interesting alternative for the epitaxial growth and/or layer transfer of III-V compounds. For proper nucleation, the wafers are precisely "off-cut" towards the appropriate direction and have been epi-cleaned. To guarantee a pristine growth surface, all production steps are closely monitored using statistical process control, and wafers are carefully inspected. At the end, there is a 100% naked-eye inspection by a trained operator.

Product highlights:

Dislocation density	0/cm² (0 EPD)
Diameter	100mm (4”) - 150mm (6”) - 200mm (8") Special diameter up to 300mm on request
Resistivity and Dopant
Minimum resistivity at 20 °C
p-type	0.005 Ω.cm
n-type	0.050 Ω.cm
Maximum resistivity at 20 °C	40 Ω.cm
Radial dispersion on a single substrate	10%
Substrate Orientation
Standard	(100) ± 0.5°
Aspect
Substrate surface finish	Standard: One side polished, one side diamond ground/etched. Upon request: Double side polished, one side prime only.
Substrate edge finish and shape	Edge ground and etched, straight or round
Roughness	Polished side < 1 nm RMS
Surface status	EPI-ready
Perpendicular strength
Minimal/Typical	3 lbf / > 6 lbf
Thickness
Diameter 100 mm (4”)	140 or 175 μm for solar cells, other thickness available upon request
Diameter 150 mm (6”)	225 μm for solar cells, other thickness available upon request
Diameter 200 mm (8")	450 µm or 625 µm, other thickness available upon request