Enhancing the breakdown voltages of Au/n-Si Schottky diodes by boron ion beam-induced edge termination

Abstract

Boron ion implantation for edge termination of Au/n-Si Schottky diode has been studied to enhance the breakdown voltages of the diodes. Ion energies of 30 and 50 keV were adopted to achieve edge-terminated Schottky diodes. Four doses of 1×10 13, 1×10 14, 1×10 15 and 1×10 16 B cm −2 were used for each energy. The Schottky diodes with edge termination show much higher breakdown voltages than the diodes without edge termination if the ion dose is controlled. For instance the diodes treated with low doses achieve high breakdown voltages while the diodes with high doses of 1×10 15 and 1×10 16 B cm −2 easily fail at low voltages showing early breakdown and high current leakage. According to the results from current–voltage ( I– V), the current leakage is reasoned to result from deep level defects introduced by B ion implantation and the leakage at a reverse bias of −40 V is maintained low up to an elevated temperature of 160°C.