| Summary: | 碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 99 === In this paper, polar free-standing (0002)GaN wafer were fabricated by
using the hydride vapor phase epitaxy(HVPE) technique on (002) LiGaO2
substrates. Polar of The (0002) GaN affects its luminous efficiency, but
compared to other surface between the substrate, it has the smallest lattice
mismatch. With the high growth rate of HVPE, hoping to grow high
quality GaN thick layer. In the self-designed reactor, Metallic gallium and
NH3 were the source of Ga and N. Nitrogen and hydrogen were used as the
carrier gases HCl and nitrogen was designed to pass through liquid Ga to
form GaCl fully. GaN deposition was realized Efficaciously by conducted
steady NH3 and GaCl flows to the substrate suface, accommodated with
additional hydrogen and nitrogen atmosphere flows.The parameters set of
research mainly focus on reaction pressure, temperature, and growth time.
In order to obtain better crystal quality, more attempts were made to grow
buffer layer by chemical vapor deposition first, then a thick GaN layer by
HVPE. The next step is to do the experiment and analyze with various
instruments. Scanning Electron Microscope and atomic force microscopy
Atomic Force Microscpoic are used to observe the surface morphology.
X-ray Diffracion and transmission electron microscopy are used to
know the lattice structure, and to understand the interface between the
substrate and the GaN film crystal structure and epitaxial relationship.
Finally, Photoluminescence spectroscopy is used to measure its optical
properties and compare its defects and epitaxial quality.
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