MOCVD에 의한 GaN stripe 위의 GaN 나노로드의 선택적 성장에 관한 연구

Abstract

Selective area growth of GaN nanostructures by metal organic vapor phase epitaxy(MOVPE) has attracted great interest due to its novel applications in optoelectronic and photonics. GaN nanorods were grown on the apex of GaN stripes by three dimensional selective growth method. SiO2 mask was partially removed only on the apex area of the GaN stripes by an optimized photolithography for the selective growth. Metallic Au was deposited only on the apex of the GaN stripes and a selective growth of GaN nanorods was followed by a metal organic vapor phase epitaxy (MOVPE). We confirmed that the shape and size of the GaN nanorods depend on growth temperature and flow rates of group III precursor. GaN nanorods were grown having a taper shape which have sharp tip and triangle-shaped cross section. From the TEM result, we confirmed that threading dislocations were rarely observed in GaN nanorods because of the very small contact area for the selective growth. Stacking faults which might be originated from a difference of the crystal facet directions between the GaN stripe and the GaN nanorods were observed in the center area of the GaN nanorods. In this work, we introduce a new growth technology of nanorods which can be grown on specific three dimensional positions. This growth technique has great potentials for the upgrade of conventional devices such as field emitters, gas censors, light emitting diodes, optical resonators and three dimensional power transistors. This technique also may propose an opening of new area for the horizontal nanowire devices interconnected between mesas and complex nanowire networks.