桥接氮化镓纳米线电致氧化特性研究

Study on the oxidation of bridging GaN nanowires induced by bias voltage

本文利用金属有机物化学气相沉积(MOCVD)方法,通过在蓝宝石衬底刻蚀沟槽的方式,制备出连接沟槽两端的桥接氮化镓纳米线。由于桥接形态纳米线在制备电极时避免了引入电极接触势垒,当大电流通过纳米线时,由于焦耳热导致纳米线从表面开始向内部发生氧化,纳米线电阻发生不可逆增大,并最终发生熔断。COMSOL模拟结果及纳米线电阻测试实验结果均表明,氮化镓纳米线在3V电压下开始被氧化,在9V电压下发生熔断。本文提供了一种原位单向精确控制纳米线电阻的方法,同时也该方法也可以进一步应用于制备多种芯包层(Core/Shell)纳米线材料。

Bridging GaN nanowires(NWs)were prepared by using metalorganic chemical vapor deposition(MOCVD).The bridging GaN NWs were grown over a deep trench on the substrate.Owning to the absence of contact barrier at the electrodes of bridging NWs,the Joule-heating can be generated mainly on the NWs itself rather than on the electrodes.The COMSOL simulation and the resistance measurement all indicated that the bridging NWs were oxidized at a bias voltage of 3V,and the thermal break down occurred at 9V.This work provides a simple method for in situ precise control of NW resistance,which can be further applied to the formation of core/shell NWs with different materials.