Amorphous Ge bipolar blocking contacts on Ge detectors

The authors report on the performance of high-purity Ge radiation detectors with amorphous Ge (a-Ge) contacts fabricated using RF sputtering techniques. Electrical contacts formed using sputtered a-Ge films on high-purity Ge crystals, both n- and p-type, were found to exhibit good blocking behavior with low leakage currents, with the contact biased under either voltage polarity. The a-Ge contacts have thin dead layers associated with them, and can be used in place of lithium-diffused, ion-implanted, or Schottky barrier contacts on Ge radiation detectors. The use of such contacts allows fabrication of multi-electrode detectors by means of simple processing steps