Metal-organic chemical vapor deposition of N-polar InN quantum dots and thin films on vicinal GaN

Abstract

N-polar InN layers were deposited using MOCVD on GaN-on-sapphire templates which were miscut 4° towards the GaN m-direction. For thin layers, quantum dot-like features were spontaneously formed to relieve the strain between the InN and GaN layers. As the thickness was increased, the dots elongated along the step direction before growing outward perpendicular to the step direction and coalescing to form a complete InN layer. XRD reciprocal space maps indicated that the InN films relaxed upon quantum dot formation after nominally 1 nm thick growth, resulting in 5–7 nm tall dots with diameters around 20–50 nm. For thicker layers above 10 nm, high electron mobilities of up to 706 cm2/V s were measured using Hall effect measurements indicating high quality layers.