Electrical characteristics of erbium-doped silicon diodes for radiation detectors

Abstract

Crystalline silicon was doped with erbium by ion implantation method at room temperature. The implanted silicon was annealed for 30 minutes at 800℃ and 1000℃. Rutherford Backscattering Spectrometry/channelling technique was used to establish the presence of erbium and to investigate the diffusion mechanisms of ion in silicon. A change in silicon crystal structure due to implantation and as a function of annealing temperature was investigated by XRD technique. In addition, Schottky diodes were successfully fabricated on unimplanted and erbium-doped silicon. The fabricated diodes were characterized using current-voltage and capacitance-voltage techniques to investigate a change in electrical properties of the diodes due to erbium doping. Effects of erbium doping on electronic parameters were discussed in this work. In general, the results indicate that in silicon erbium is responsible for relaxation behaviour of the material. A material exhibiting relaxation behaviour is resistant to radiation-damage. Thus, erbium is a promising dopant to improve radiation-hardness of silicon to be used for fabrication of radiation detectors to meet the current and future requirements for high energy physics experiments.