Optical and Crystalline Properties of Epitaxial-Lateral-Overgrown-GaN Using Tungsten Mask by Hydride Vapor Phase Epitaxy

The epitaxial lateral overgrowth (ELO) of GaN with a stripe tungsten (W) mask pattern is performed by hydride vapor phase epitaxy (HVPE) and a buried structure of the W mask with a smooth surface is achieved for the stripe mask patterns of <1120> and <1100> direction. Optical and crystalline characteristics of the ELO-GaN are investigated by means of cathodoluminescence (CL) imaging and X-ray rocking curves (XRCs). It is found that the CL intensity at 133 K due to the near-band edge emission is stronger in the laterally overgrown region in comparison with that in the normal growth region. The φ-ω scan of XRCs reveals that the tilting of the c-axis is much smaller in the ELO-GaN grown with the W mask than that grown with an SiO2 mask.