Lithium-Diffused n+ Contacts on High-Purity Germanium Detectors: How Thin Can They be Made-How Stable Are They?

A Li-diffused n+ surface layer is the best n+ contact developed up to the present time. However, the effective dead layer resulting from the Li-diffusion prevents the optimum stacking of detectors for counter telescopes. Diffusion temperatures as low as 160°C have been successfully used to produce effective dead layers as thin as 10 ¿. Unfortunately, these dead layers increase significantly when the detector is annealed following radiation damage.