| Summary: | 碩士 === 國立臺灣大學 === 光電工程學研究所 === 107 === Using a patterned sapphire substrate(PSSs) in the Aluminum nitride thin film can reduce the threading dislocation density and increase the crystal quality, and reduce the defect density. Due to the size of commercial patterned sapphire substrate is micronmeter, the coalescence thickness will be higher approximately 8 to 12 micronmeter. We used ebeam lithgrophy and wet-etching technology to fabricate nano-PSS and successfully growth the 3um AlN thin film which already coalescence and reduce defect density from 3.25x〖10〗^9 〖cm〗^(-2) to 4.8x〖10〗^8 〖cm〗^(-2).
At the final stage, we used raman system to analyze AlN which growth on patterned sapphire with the change between top c-plane size and period.Accroding the result of FWHM and residual stress, we establish the growth mechanism model of AlN.Finally we prove it with SEM,AFM,TEM.
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