"自上而下"法制备高性能GaN纳米线阵列

针对自下而上生长GaN纳米线的尺寸、形态、取向不易控制的问题,文中采用自上而下刻蚀的方法来制备GaN纳米线材料。以图形化的金属Ni作为掩膜对GaN进行ICP刻蚀,系统研究了刻蚀参数,主要是ICP功率以及RF功率对GaN纳米线形貌以及拉曼、PL光谱的影响,同时也对比了干法刻蚀后,有无湿法处理的影响。研究发现,当ICP功率为1 000 W,RF功率为100 W时,GaN纳米线的拉曼和PL光谱强度较大,表明此功率下刻蚀的纳米线损伤较小。经过KOH浸泡30 min后,GaN纳米线的形貌得到了改善,拉曼和PL光谱强度均优于单纯的干法刻蚀,为下一步器件的制备提供了良好的材料基础。

Preparation of High Performance GaN Nanowire Arrays by Top-down Method

In this paper, the top-down etching method is used to fabricate GaN nanowires for solving the problem that the uncontrollable of the size, morphology and orientation of GaN nanowires grown from bottom. ICP dry etching was used on GaN epitaxy with patterned metal Ni as a mask. The etching parameters were systematically studied, and the effects of ICP power, RF power and wet etching on the morphology, Raman and PL spectra of GaN nanowires were also been investigated. It has been found that when the ICP power is 1000 W and the RF power is 100 W, the intensity of Raman and PL spectra of the GaN nanowires are relatively strong, indicating that the nanowires etched under this condition are with less defects. After immersion in KOH for 30 min, the morphology of GaN nanowires was improved. The intensity of Raman and PL spectra was better than that of only with dry etching, which provided a good nanowires for the preparation of the device application.