Metal-organic chemical vapor deposition of high quality, high indium composition N-polar InGaN layers for tunnel devices

摘要

In this study, the growth of high quality N-polar InGaN films by metaiorganic chemical vapor deposition is presented with a focus on growth process optimization for high indium compositions and the structural and tunneling properties of such films. Uniform InGaN/GaN multiple quantum well stacks with indium compositions up to 0.46 were grown with local compositional analysis performed by energy-dispersive X-ray spectroscopy within a scanning transmission electron microscope. Bright room-temperature photoluminescence up to 600 nm was observed for films with indium compositions up to 0.35. To study the tunneling behavior of the InGaN layers, N-polar GaNZIn_(0.35)Ga_(0.65)N/GaN tunnel diodes were fabricated which reached a maximum current density of 1.7 kA/cm~2 at 5 V reverse bias. Temperature-dependent measurements are presented and confirm tunneling behavior under reverse bias.