Umicore has perfected the Czochralski crystal-growth method  specifically for germanium, enabling the production of the world’s purest germanium crystal -- with a record purity of 99.99999999999%. Umicore is currently the only manufacturer capable of achieving this exceptional level of crystal quality.
These ultrapure crystals are used to detect and analyze gamma rays in particle accelerators, nuclear power plants and space mission applications, such as the gamma ray spectrometer on the Mars Odyssey spacecraft that discovered water across Mars. Today, ultrapure germanium crystals are being used to build a major instrument designed to detect dark matter in  the universe.Â
Umicore continues to innovate and advance its germanium-crystal production technology, reinforcing our leadership in germanium substrates for high-precision space applications.
Product highlights:
The crystals are Czochralski grown in the (100) crystallographic direction. The outer crystal surface is as grown or cylindrically ground (surface roughness max 2.5 μm RMS). The crystal soundness is checked by infrared thermography.
- Transport properties - Hall mobility μH
- p-type μH ≥ 10 000 cm2/V.s (Center measurement)
- n-type μH ≥ 10 000 cm2/V.s (Center measurement)
- Deep levels (measured by DLTS)
- p-type : Cutot ≤ 4,5 109 cm-3
- n-type : Deep level point defects < 5 108 cm-3
- Crystallographic perfection:
| Â | p-type | n-type |
| Dislocation density (EPD, cm2) |  ≤ 10 000 |  ≤ 5 000 |
| Lineage (unit length = slice radius) |  ≤ 4 |  ≤ 3 |
| Mosaic structures (unit surface = 10 mm2) |  ≤ 6 |  ≤ 3 |
| Saucers (cm2) |  ≤ 500 |  ≤ 500 |