Influence of the growth temperature of AlN nucleation layer on AlN template grown by high-temperature MOCVD

We studied the influence of the growth temperature of AlN nucleation layer (T-NL) on the AlN template grown by high-temperature metal-organic chemical vapor deposition (HT-MOCVD). The AlN templates were characterized by high-resolution X-ray diffractometer, atomic force microscopy and room-temperature Raman scattering spectrometer. The results revealed that the T-NL had a direct influence on the quality of the AlN template. By optimizing the T-NL at 950 degrees C, we obtained a high-quality AlN template with the full width at half maxima for the (0002) and (10-12) planes of 90 '' and 612 '', respectively. The AlN template also presented atomic level step with a root mean square (RMS) roughness of 0.133 nm. In addition, it performed excellent single crystallographic orientation along the c-axis. The growth evolution of AlN nucleation layer at different T-NL was also explained in detail. (C) 2013 Elsevier B.V. All rights reserved.