Effect of High NH₃Input Partial Pressure on Hydride Vapor Phase Epitaxy of InN Using Nitrided (0001) Sapphire Substrates

Abstract

The influence of the source gas supply sequence prior to growth and the NH 3 input partial pressure (Pº NH3 ) on the nucleation of InN islands during the initial stages of hydride vapor phase epitaxy on a nitrided (0001) sapphire substrate was investigated.The crystalline quality of the InN layer after subsequent lateral growth was also examined. When NH 3 was flowed prior to growth, single-crystal hexagonal InN islands formed. When InN was grown with a higher Pº NH3 , the number of InN islands decreased remarkably while their diameter increased. The crystalline quality of InN grown on the hexagonal islands with a high Pº NH3 significantly improved with increasing growth time.A strong PL spectrum was observed only from InN layers grown with a high Pº NH3 . It was thus revealed that an NH 3 preflow and a high Pº NH3 are effective for producing InN with high crystalline quality and good optical and electrical properties.