  Radiation detectors constructed from large volume high purity Ge (HPGe)
single crystals are widely used for gamma-ray spectroscopy. The detectors for
this application can be simple in that they need only have two electrical
contacts for voltage application and signal readout. Such HPGe based detectors
have been commercially produced for many decades using standard semiconductor
fabrication processes. For the applications of gamma-ray imaging and particle
tracking, however, interaction position measurement within the detector as well
as the measurement of the deposited energy is required. This necessitates a
more complex detector often with the electrical contacts divided into a large
number of segments that can be individually instrumented for signal readout.
The reliable and cost-effective implementation of contact segmentation with the
standard commercial processes is a challenge. An alternative fabrication
technology based on thin film amorphous semiconductor layers was developed at
Lawrence Berkeley National Laboratory (LBNL) and can be used to produce finely
segmented, fully passivated HPGe detectors. Over the last almost two decades, a
large number of segmented contact HPGe detectors have been produced at LBNL
using this technology. This paper provides a set of procedures that has been
used at LBNL for the manufacture of the segmented amorphous semiconductor
contact HPGe detectors.
