Figure  3a,b,c,d shows surface morphologies and cross section of In x Al1-x

N films which were prepared on Si(100) with different In/Al ratios. Also, the surface roughness is larger than in other reports [28] due to high-density grain boundaries and island growth. Besides, the grain size of In x Al1-x N decreases with the increase of TMIn mass flow which may be due to the indium interstitials. Thus, both AFM and SEM measurement results show that the use of smaller TMIn mass flow leads to a reduction in the surface roughness of the InAlN film. Also, the thickness of the grown InAlN in this study was increased with increasing AZD1480 TMIn mass flow. Besides, growth rates of all InAlN films were around 0.35 μm/h at x = 0.57, 0.43 μm/h at x = 0.64, 0.5 μm/h at x = 0.71, and 0.6 μm/h at x = 0.80, respectively. Moreover, the surface of In0.80Al0.2 N film was clearly observed to be rough, as compared with those of the other reports of In x Al1-x N layers [16]. Figure  3e shows that the growth rate depended on the TMIn mass flow. It is clearly seen that by increasing the TMIn/TMAl flow ratios from 1.29 to 1.63, the growth rate of the films was increased from 0.35 to 0.6 μm/h. However, the increase of the surface roughness with the increase of growth rate may be due to the 3-D growth mode. The insets in Figure  3e show the AFM images corresponding to SEM images of the surface morphologies for

the InAlN films. Figure 3 SEM cross-sectional images. (a-d) Top-view and cross-sectional SEM images of In x Al1-x N films. (e) selleck inhibitor Growth rate of InAlN films with various In compositions. Figure  4a shows a cross-sectional bright-field TEM image Amino acid of the In0.71Al0.29 N film. The image clearly shows that the structural characteristics of the In0.71Al0.29 N film

exhibited a rough surface and columnar structure at the cleavage. In addition, selleck kinase inhibitor existence of no metallic In inclusions can be observed in the images which agree with the XRD results. Besides, the selected-area diffraction pattern (SAD) reveals InAlN/Si reflections shown Figure  4b. Individual diffraction rings can be identified as InAlN reflections, indicating that it is a polycrystalline InAlN film with preferred c-axis. Figure 4 TEM images of the cross section of In 0.71 Al 0.29   N/Si. (a) Cross-sectional TEM image and (b) the SAD pattern from the In0.71Al0.29 N film. Figure  5a shows the high-angle annular dark-field (HAADF) cross-sectional image of the In0.71Al0.29 N film which is taken in the [110]Si zone axis projection. The image shows that the two layers are visible. The top layer exhibited a thickness of about 420 nm which was measured at an indium content x of approximately 0.71 by scanning transmission electron microscopy with energy-dispersive spectroscopy (STEM-EDS). The bright layer of about 80 nm was observed at bottom regions which are indium-rich.