Formation of Solid Solution of Al1-xSixN (0

When Si was doped into an AlN layer during metalorganic vapor-phase epitaxial growth, the Al density (NAl) in the AlN layer decreased but the N density (NN) did not change. The decrease in NAl was almost the same as the Si density (Nsi). As Nsi increased in Si-doped AlN, the lattice constant decreased. These results can be explained by Si atoms replacing Al atoms in Si-doped AlN and subsequent Si–N bond formation. Thus, Si-doped AlN becomes a substitutional solid solution of Al1-x Si x N ternary alloy. The highest Si density at which the x-ray diffraction peak still appears was 5.8×1021 cm-3 (x=12%).