Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1572426 | Materials Characterization | 2007 | 8 Pages |
Dry thermal oxidation of low defect density aluminum nitride single crystals was investigated by high resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). Oxidation at 800 °C produced an amorphous oxide layer. In the AlN near the interface were many dislocations, stacking faults and domain boundaries, molecular nitrogen and oxygen. Oxidation at 1000 °C produced a crystalline, epitaxial oxide layer with several large grains and twin structures. Near the interface, the oxide was single phase α-Al2O3, while near the surface the oxide was a mixture of γ-Al2O3 and α-Al2O3. The AlN crystal structure was nearly defect- and oxygen-free. The epitaxial relationship between Al2O3 and AlN was (0001) AlN // (011¯1¯) Al2O3 and [11¯00] AlN // [011¯1] Al2O3.