An Al_0.25Ga_0.75N/GaN Lateral Field Emission Device with a Nano Void Channel

We report an Al_0.25Ga_0.75N/GaN based lateral field emission device with a nanometer scale void channel. A \sim45 nm void channel is obtained by etching out the SiO_2 sacrificial dielectric layer between the semiconductor emitter and the metal collector. Under an atmospheric environment instead of vacuum conditions, the GaN-based field emission device shows a low turn-on voltage of 2.3 V, a high emission current of \sim40 \muA (line current density 2.3 mA/cm) at a collector bias V_\rm C=3 V, and a low reverse leakage of 3 nA at V_\rm C=-3 V. These characteristics are attributed to the nanometer scale void channel as well as the high density of two-dimensional electron gas in the AlGaN/GaN heterojunction. This type of device may have potential applications in high frequency microelectronics or nanoelectronics.