When Si was doped into an AlN layer during metalorganic vapor-phase epitaxi
al growth, the Al density (N-Al) in the AlN layer decreased but the N densi
ty (N-N) did not change. The decrease in N-Al was almost the same as the Si
density (N-si). As N-si increased in Si-doped AlN, the lattice constant de
creased. These results can be explained by Si atoms replacing Al atoms in S
i-doped AlN and subsequent Si-N bond formation. Thus, Si-doped AlN becomes
a substitutional solid solution of Al1-xSixN ternary alloy. The highest Si
density at which the x-ray diffraction peak still appears was 5.8 x 10(21)
cm(-3) (x = 12%).