A high quality InAlGaN quaternary alloy grown on c-plane sapphire substrates under H-2 and N-2 environments by metal-organic vapor phase epitaxy

作者：Kim Jongmin^*; Song Keun Man; Shin Chan Soo; Ko Chul Gi

来源：Journal of Ceramic Processing Research, 2011, 12: S211-S214.

• Metalorganic vapor phase epitaxy
• Nitrides

Quaternary InAlGaN layers were grown on c-plane sapphire substrates with different TMAI flow rates, V/III ratios, growth rates, and carrier gases by metal-organic vapor phase epitaxy (MOVPE). The effects of TMAI flow rates, V/III ratios, growth rates, and carrier gases on the structural, electrical, and optical properties of InAlGaN were investigated. The peak angle separation between InAlGaN and GaN has a similar trend for N-2 and H-2 environments. It is revealed that the incorporation efficiency of aluminum under a N-2 environment is larger than that under a H-2 environment from the PL peak measurements. The PL intensity of InAlGaN grown at a V/III ratio of 3350 is maximal. At a growth rate of 0.9 nm/minute, the PL intensity of InAlGaN is maximal. Above and below 0.9 nm/minute, the PL intensity decreases due to a deterioration in crystal quality. The surface morphology of InAlGaN was also investigated by AFM. AFM images (4 mu m X 4 mu m) show smooth surfaces and step-flow growth although pits are still observed on AFM images. The sheet carrier density slightly decreased from 1.3 x 10(13) to 9.6 x 10(12) cm(-2) due to a slight deterioration in the crystal quality of InAlGaN as the band offset increased from 0.208 to 0.298 eV. However, the electron mobility increased from 685 to 1050 cm(2)/V.s.

• 出版日期2011-11