| Summary: | 碩士 === 國立彰化師範大學 === 電子工程學系 === 99 === The effect of buffer layer structure, growth temperature and V/III ratio on the film quality of In rich InGaN thin films grown by molecular beam epitaxy have been explored. First, adding the buffer layer structure to InGaN with about 80% of indium content reduces dislocation density from 5.3x1010cm-2 to 2.94x1010cm-2 and suppresses phase separation.
InGaN films were grown at 540℃，550℃，560℃. The surface morphology shows improved roughness as the growth temperature increases, however, the crystal structure quality degrads. Highest photoluminescence(PL) intensity and narrowest peak width are found on the film grown at 550℃, indicating it is the optimized growth temperature.
V/III ratio is modulated to InGaN. The best surface roughness of 1.67nm and the best photoluminescence FWHM of 32meV occur when the group III is increased for 6%. However, the edge type dislocation density shows a higher value of 7.1x1010cm-2.
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