Presentation Information
[25p-21C-1]Structural and morphological investigation of N-polar InGaN epilayers grown on misoriented ScAlMgO4 substrates
〇(D)Mohammed Ali Najmi1, Pavel Kirilenko1, Daisuke Iida1, Kazuhiro Ohkawa1 (1.King Abdullah Univ. of Science and Technology)
Keywords:
InGaN,ScAlMgO4 (SAM)
ScAlMgO4 (SAM) substrates are potential candidates for growing high-quality InGaN-based layers, that have great potential for high InN-molar-fraction InGaN-based yellow-red light-emitting diodes and laser diodes [1]. In general, high InN-molar-fraction in InGaN active regions results in a larger in-plane lattice constant, which introduces significant defects due to increased lattice mismatch with the underlying GaN layers. To overcome this issue of high defects density we have previously utilized this substrate by directly growing InGaN on SAM with no buffer layer [2].
In this work, we demonstrate the growth of N-polar InGaN layers on misoriented SAM substrates with offset of 0.3° to 5.8° toward the m-plane. The surface morphology of the N-polar InGaN with small-offset substrates has shown hexagonal hillocks as typically observed in N-polar GaN epilayers. On the contrary, the InGaN growth on larger misorientation angles of SAM substrate resulted in smoother surfaces. In contrast, the crystalline quality of InGaN indicated an opposite trend with significantly improved quality observed at smaller misorientation angles. We obtained an unprecedented crystalline quality of N-polar InGaN using SAM substrates with a 0.5° offset, which exhibited a X-ray rocking curve (XRC) full width at half maximum (FWHM) value of 223 arcsec [3].
In this work, we demonstrate the growth of N-polar InGaN layers on misoriented SAM substrates with offset of 0.3° to 5.8° toward the m-plane. The surface morphology of the N-polar InGaN with small-offset substrates has shown hexagonal hillocks as typically observed in N-polar GaN epilayers. On the contrary, the InGaN growth on larger misorientation angles of SAM substrate resulted in smoother surfaces. In contrast, the crystalline quality of InGaN indicated an opposite trend with significantly improved quality observed at smaller misorientation angles. We obtained an unprecedented crystalline quality of N-polar InGaN using SAM substrates with a 0.5° offset, which exhibited a X-ray rocking curve (XRC) full width at half maximum (FWHM) value of 223 arcsec [3].