Groove Detectors from High-Purity Germanium

Detector have been fabricated from pure germanium with a lithium diffused N+ contact, and a P+ contact which is ion implanted in a dc glow discharge in boron trifluoride. A deep groove is used to increase the breakdown voltage. Measurements of the current-voltage characteristics of these detectors after temperature cycling are reported. The correlation of smooth etch pits with severe trapping in pure germanium detectors is shown. Finally, the performance of a few large detectors is given.