Growth of lattice-relaxed InGaN thick films on patterned sapphire substrates by tri-halide vapor phase epitaxy

Abstract

Lattice-relaxed thick InGaN films could be obtained using patterned sapphire substrates (PSSs) by tri-halide vapor phase epitaxy. Furthermore, by inserting the GaN intermediate layer between the InGaN epilayer and the PSS, the crystalline quality of the InGaN epilayer was drastically improved. According to the X-ray diffraction ω-rocking curve measurements, the full width at half maximum of the InGaN epilayer was 850 arcsec around the symmetrical reflection and 967 arcsec around the skew-symmetrical reflection. It was also found that the thickness of the GaN intermediate layer influences the crystalline quality of the InGaN epilayer. As the thickness of the GaN intermediate layer increases, the crystalline quality of the GaN intermediate layer gets higher, resulting in the crystalline quality of the InGaN epilayer was improved.