Growth parametric study of N-polar InGaN films by metalorganic chemical vapor deposition

• N-polar InGaN films were grown on high quality N-polar GaN/sapphire.
• We studied the influences of 4 growth parameters on the properties of InGaN films.
• High growth pressure increased the In content and promoted the crystal quality.
• High growth temperature improved the crystal quality and the optical properties.
• N-polar InGaN film with green-emitting at 530 nm is obtained.

We report the growth of N-polar InGaN alloy films on high-quality N-polar GaN templates with smooth surface by metal organic chemical vapor deposition. In this work, we systematically investigate the influences of growth parameters, such as growth temperature, pressure, V/III source ratio and trimethylindium input flow on the crystalline and optical properties of N-polar InGaN films. It is found that the relatively high growth pressure can promote the incorporation of In atoms into InGaN films and improve the crystalline quality by enhancing the epitaxial lateral overgrowth without mask simultaneously. Also, relatively low growth temperature, small V/III ratio and large trimethylindium input flow are more effective ways to increase In content in the films. Besides, we find that a high growth temperature is beneficial to improve the optical properties of InGaN films. Finally, N-polar InGaN film with green-emitting at 530 nm is obtained.