초록 열기/닫기 버튼
An epitaxial GaN layer was grown on a cone-shape-patterned sapphire substrate (PSS) (Sample A) and anAlN-buffered PSS (Sample B) with two growth steps under the same process conditions by employing the hydride vaporphase epitaxy (HVPE) method. We have investigated the characteristics of the GaN layer grown on two kinds ofsubstrates at each growth step. The cross-sectional SEM image of the GaN layer grown on the two types of substratesshowed growth states of GaN layers formed during the 1st and 2nd growth steps with different growth durations. Dislocation density was obtained by calculation using the FWHM value of the rocking curve for (002) and (102). SampleA showed 2.62+08E and 6.66+08E and sample B exhibited 5.74+07E and 1.65+08E for two different planes. The redshift was observed is photoluminescence (PL) analysis and Raman spectroscopy results. GaN layers grown onAlN-buffered PSS exhibited better optical and crystallographic properties than GaN layers grown on PSS.
