Stabilization of lithium-drifted silicon surface-barrier detectors

Abstract A simple fabrication technique has been found which yields lithium-drifted silicon surface-barrier detectors which have a low leakage current and which exhibit stable electrical and α-particle characteristics under conditions of prolonged aging and repeated exposure to thermal-vacuum environments. The detectors will operate at a temperature of 65°C and high vacuum for several days with no evidence of noise instability. The operating characteristics of such detectors have been studied over a period of several months. These studies included measurements of their electrical and α-particle characteristics taken before, during, and after thermal-vacuum testing at 65°C and additional testing at 50°C. Degradation in electrical and α-particle characteristics resulting from such testing and aging was found to be negligible over a period of approximately four months. The measurements at 50°C and 65°C indicate that the fractional change in the mean energy per ion pair is approximately −1.3 × 10 −4 /°C over the temperature range from room temperature to 65°C. The results of these studies are reported.