Fabrication of a planar P type high purity germanium detector

High Purity germanium (HPGe) detectors are found to be suitable for nuclear techniques for measuring radionuclides with very good energy resolution. Formation of charge non-injecting contacts and intercontact surface passivation to achieve low leakage current are two foremost challenges associated with the HPGe detector fabrication. As a result, the fabrication recipes of commercially available detectors are proprietary in nature. Existence of a space charge layer at the free surface of germanium is a well identified problem which makes the surface conductivity of Ge different from that of the bulk. The objective of this work is to demonstrate the functionality of a planar p type HPGe detector fabricated by circumventing the complex ion implantation process. Electrical and detection properties of the prototypes have been characterized, showing low leakage currents and good spectroscopy data with different gamma-ray sources. P-Type HPGe detector was successfully fabricated using Li and Au contacts employing indigenously developed tools and set-ups. Need for complex ion implantation process could be eliminated using oxidation etch and subsequent Au evaporation. However, it needs to be emphasized that rugged rectifying contact on N type crystal may still require ion implantor tool. In future, the technology will be scaled up to fabricate large volume detectors