Fabrication of lithium-drifted silicon detectors by constant temperature method

Abstract

A new approach for lithium drifting in silicon is described where the silicon devices under drift are held at constant temperature and bias at normal air ambient, and the drift process is terminated at the end of an estimated time depending upon the thickness of wafers. A 4-channel lithium drifting unit with electronically controlled oven has been constructed for this purpose. Full details of the fabrication procedure are given. A sizable number of Si(Li) detectors have been fabricated using this approach. The quality of the detectors is tested with ²⁴¹Am alphas and conversion electrons from ²⁰⁹Bi and ¹³⁷Cs sources. The detectors are regularly used for nuclear physics experiments at this Centre.