Characteristics of silicon surface barrier radiation detectors for alpha particle detection

Abstract

Silicon surface barrier (SSB) radiation detectors with various electrode structures were designed and fabricated to extract an optimal structure for detecting charged particles with high sensitivity. There are two main considerations in this study. One is a guard electrode structure to minimize reverse-bias leakage currents and the other is the size of the active area to achieve a relatively high-energy resolution for its application. Two different semiconductor fabrication processes were incorporated. The contribution of an etching process, which is one of the semiconductor fabrication processes affecting a detector's performance, was also investigated. Reverse-bias leakage currents of the guard-configured SSB radiation detectors can be minimized by about ten times compared with those of the plain planar-type SSB radiation detectors in both an etching case and a non-etching case. Improved energy resolutions for alpha particles from Pu-238 were also observed in both cases. The diameters of the active areas of the plain planar-type SSB radiation detectors were varied from 8 mm to 1 mm to determine the optimal active area by comparing the energy resolutions. From this study, the characteristics of SSB radiation detectors due to an incorporation of a guard electrode, including the size of an active area, were investigated for their proper application, such as high-energy charged-particle detection in an accelerator and radon detection in air. Two different fabrication processes were also addressed.