High Purity Germanium Crystals

solid cylindrical high purity Ge crystals capable of serving as high-resolution ionization detectors. Following procurement, the crystals will be shaped and polished into uniform 100mm diameter, 33.33mm long cylinders aligned to the (100) crystal axis. The following specifications shall be met for each crystal: 1. The crystal shall be grown from high purity Ge 2. Crystal growth orientation shall be aligned with the (100) axis to within 1 degree 3. Diameter of unshaped disks shall be sufficiently large to allow a final diameter of 100mm after alignment to (100) crystal axis 4. Length of unshaped disks shall be 35mm 5. Etch pit density shall be less than 5000/cm2 6. There shall be no slippage of the crystal planes 7. Impurity concentration shall be less than 2.5×1010 /cm3 8. The crystal shall be undoped N-type 9. 4mm thick witness wafer immediately adjacent to the crystal shall be provided from the crystal face furthest from the center of the boule 3ea 100mm dia 3ea 4mm thk