Abstract:

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.

Key words: GaN, nanowires, Ni mask, ICP etching, wet etching, morphology of sidewall