Metal-doped silicon diodes for radiation sensing applications

Crystalline silicon (Si) of different concentration types was doped with iron (Fe) and cadmium (Cd) metals. The doping was achieved by implantation of Si with metals at an energy of 160 keV.  Different material characterization techniques were used to confirm the presence of the metals in Si prior to the fabrication of Schottky diodes. Schottky diodes fabricated on unimplanted and metal-implanted Si were characterized at room temperature using current-voltage (I-V) and capacitance-voltage (C-V) techniques to investigate a change in electrical properties of the diodes due to metal doping.  The diodes were then irradiated by 4 MeV protons and re-characterized to establish a change in diode properties due to irradiation. A change in different diode parameters due to metal doping and irradiation was also investigated. The results were explained in terms of the defects induced by metals in Si and are important for an ongoing quest to improve the efficiency of Si radiation detectors for current and future high-energy physics experiments and other applications. It was suggested for the first time, that Fe and Cd were suitable dopants in a study to improve the radiation hardness of Si through the defect-engineering method in this work.