Transmission electron microscope (TEM) and transmission electron diffraction (TED) examination has been performed to investigate microstructural properties of gas source molecular beam epitaxial GaN(As,P) layers grown on (0001) GaN/sapphire at temperatures in the range 500 - 760°C. As for the GaNAs, we report the observation of ordering with a space group P3m1 in the layer grown at 730°C. The layers grown at temperatures below 600°C are polycrystalline, whist the 730°C GaNAs layer has epitaxial relation to the GaN substrate. It is also shown that the GaNAs layers experience a structural change from a zinc-blende phase to a wurtzite phase, as the growth temperature increases. As for the GaNP, it is shown that the layers grown at temperatures ≤ 600°C experience phase separation resulting in a mixture of GaN-rich and GaP-rich GaNP with zinc-blende structure. However, the layers grown at temperatures ≥ 730 °C are found to be binary zinc-blende GaN(P) single crystalline materials. The layers grown at temperatures ≥ 730°C consist of two types of micro-domains, i.e., GaN(P) I and GaN(P) II; the former having twin relation to the latter.
|Journal||MRS Internet Journal of Nitride Semiconductor Research|
|Issue number||SUPPL. 1|
|Publication status||Published - 1999|
ASJC Scopus subject areas
- Materials Science(all)