Sulfur passivation for thermal stability enhancement of RuO2 Schottky contact on compound semiconductor

We have studied the thermal stability of the electrical properties for RuO₂ Schottky contact on sulfur passivated n-type GaAs. The sulfur passivation on the surface of the compound semiconductor was done with (NH₄)₂S_x solution under 150 watt light illumination at room temperature, and then RuO₂ contacts were fabricated by a DC magnetron sputtering method. By the sulfur passivation on semiconductors the RuO₂ Schottky contacts showed the good electrical properties and enhancement of its thermal stability during the thermal annealing upto 550°C for 10 min. From AES(Auger electron spectroscopy) analysis, it was confirmed that the sulfur passivation is responsible for the suppression of an oxidation at interfaces between RuO₂ and semiconductors.