EFFECT OF SHROUD FLOW ON HIGH-QUALITY INXGA1-XN DEPOSITION IN A PRODUCTION SCALE MULTI-WAFER-ROTATING-DISC REACTOR

High quality InGaN thin films and InGaN/GaN double heterojunction (DH) structures have been epitaxially grown on c-sapphire substrates by MO CVD in a production scale multi-wafer-rotating-disc reactor between 77 0 to 840 degrees C. We observed that shroud flow (majority carrier gas in the reaction chamber) is the key to obtaining high quality InGaN t hin films. High purity H-2 as the shroud flow results in poor crystal quality and surface morphology but strong photoluminescence (PL) at ro om temperature. However, pure N-2 as the shroud flow results in high c rystal quality InGaN with an x-ray full width at half maximum (FWHM)(I nGaN(0002)) of 7.5 min and a strong room temperature PL peaking at 400 nm. In addition, InGaN/GaN single heterojunction (SH) and DH structur es both have excellent surface morphology and sharp interfaces. The fu ll width at half maximum of PL at 300K from an InGaN/GaN DH structure is about 100 meV which is the best reported to date. A high indium mol e fraction in InGaN of 60% and high quality zinc doped InGaN depositio ns were also achieved.