THREE-DIMENSIONAL AlGaAs NANO-HETEROSTRUCTURES USING BOTH VLS AND MOVPE GROWTH MODES

摘要

Three dimensional (3D) nano-heterostructures can be fabricated using both the vapor-liquid-solid (VLS) and metalorganic vapor phase epitaxy (MOVPE) growth modes. This technique is fundamentally a bottom-up approach and represents a new nano-technology. In the growth of AlGaAs nanowires, GaAs, AlGaAs, and AlAs wires are oriented to the [111]B direction on GaAs(311)B substrates. Heterostructures were grown in nanowires capped with AlGaAs layers formed by the MOVPE growth mode. SEM images of the heterostructures in nanowires, which were repeated to the [111]B direction, were clearly observed. Since Au particles are always on the top surface, the VLS and MOVPE growth modes can be repeated. We have successfully made twice-repeated heterostructures and clearly observed the first and second heterostructure wires in cross-sectional SEM images. These fabrication techniques for 3D nano-heterostructures will be useful for device applications.