Activity modulation MEE growth of 2H‐AlN on Si(111) using double buffer layer grown by PA‐MBE

Abstract

AbstractAs a demonstration of the activity modulation migration enhanced epitaxy (AM‐MEE) heteroepitaxial 2H‐AlN thin films of 53.8 nm and 171.3 nm thickness on Si(111) on a double buffer layer (DBL) have been grown by the AM‐MEE of plasma assisted molecular beam epitaxy (PA‐MBE) method. It is a droplet free growth and an atomic layer epitaxy (ALE). The influence of the DBL, which was formed in a MBE chamber before the AM‐MEE growth of 2H‐AlN thin films on Si(111), was studied to improve the crystallinity of AlN films. For the growth of high quality 2H‐AlN on Si(111), the optimization of growth of the DBL. The interface roughness of the DBL as a layer between two layers of AlN and Si, AlN/DBL/Si was characterized by grazing incidence X‐ray reflectivity (GIXR) and the surfaces were observed by AFM. Full width at half maximum (FWHM) of ω /2θ for 53.8 nm and 171.3 nm thickness AlN (0002) films were 12.1 arcmin and 7.1 arcmin, respectively. AFM images showed droplet free growth after the AM‐MEE and importance of the preparation of initial clean Si surface. Unifrom formation of DBL on a large size wafer of Si was available to use indirect exposure of N radical atoms. By increasing the thickness of the AlN the crystallinity was improved but the surface roughness of AlN did not depend on the thickness of the AlN films obtained by fitting results of GIXR curves. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)