Influence of carrier gas on the morphology and structure of GaN layers grown on sapphire substrate by six-wafer metal organic chemical vapor deposition system
Hx. Wang et al., Influence of carrier gas on the morphology and structure of GaN layers grown on sapphire substrate by six-wafer metal organic chemical vapor deposition system, J CRYST GR, 233(4), 2001, pp. 681-686
The influence of hydrogen and nitrogen III-carrier gas mixture on the GaN l
ayers grown at a high temperature of 1100 degreesC by a novel six-wafer met
al-organic chemical vapor deposition (MOCVD) were studied using optical mic
roscopy, X-ray diffraction (XRD), and photoluminescence (PL). The different
ratio of nitrogen and hydrogen of III-carrier gas strongly affect the grow
th mechanism of GaN layers. In the case of higher ratio of N-2/(N-2 + H-2),
the surface shows a hillock morphology. On the other hand, with decreasing
the flow rate of N-2 to a smaller ratio of N-2/(N-2 + H-2), the surface sh
ows a mirror like morphology. In this case, the growth rate was also decrea
sed. The measurement of X-ray diffraction (XRD) shows that the FWHM of XRD
rocking curve of sample grown with smaller flow rate of N-2 becomes wider.
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