Lattice parameters of wurtzite Al1−xSixN ternary alloys

Lattice constants and bond lengths of wurtzite Al1−xSixN ternary alloys (0⩽x⩽0.08) were determined by reciprocal lattice maps around Al1−xSixN (0002) and (11–24) reflections. The measured lattice constants obtained directly from as-grown Al1−xSixN layers were scattered because they include the factor of residual strain. Therefore, the lattice constants in the strain-free case were calculated from the measured lattice constants taking the residual strain into account. We found that the a-axis and c-axis lattice constants of the strain-free Al1−xSixN linearly decreased with the Si content as a0=3.1113−0.1412x (Å) and c0=4.9814−0.2299x (Å). Further, we obtained the bond length as d0=1.86818−0.0862x (Å). The bond length is nearly equal to the interpolation between the Al–N bond and the Si–N bond.