Electrical characterization of interface stability between magnesium and selenium-passivated n-type silicon (001)


We reported selenium passivation of silicon (001) surface and showed the ohmic nature of the interface between magnesium and selenium-passivated n -type silicon (001). In this paper, we present a detailed study on the thermal stability of this interface. Magnesium contacts on selenium-passivated silicon (001) are annealed from 200°C to 500°C at an interval of 50°C and then characterized by current-voltage measurements. Schottky barrier heights of the contacts are measured by capacitance-voltage and activation-energy methods. Schottky behaviour sets in only when the interface is subjected to annealing above 375°C. On the contrary, magnesium contacts on bare silicon (001) turn from ohmic to Schottky at much lower temperatures. The temperature difference is 50-150°C. We deduce that selenium passivation suppresses silicidation between magnesium and silicon, because it reduces the surface reactivity of silicon by eliminating dangling bonds and relaxing strained bonds.

Publication Title

International Journal of Electronics