The fabrication technique and electrical properties of a free-standing GaN nanowire

We fabricated a free-standing structure of a GaN nanowire by selectively etching Si₃N₄, previously grown on a SiO₂ substrate, for application to three-dimensional integrated circuits such as nanorelays and actuators. In the nanowire-deposition process we adopted electrophoresis and reactive ion etching techniques to achieve a well-aligned and free-standing nanowire. The electrical transport measurements were performed from room temperature down to liquid-nitrogen temperature. The current-voltage (I-V) characteristics showed a rectifying behavior in the whole temperature range. We analyze this property as a Schottky barrier formation between the nanowire and electrodes.