Surface and in-depth characterization of InGaN compounds synthesized by plasma-assisted molecular beam epitaxy

Low-temperature grown wurtzite InxGa1−xN thin films via hollow cathode plasma-assisted atomic layer deposition

“…Although In x Ga 1Àx N films exhibit higher N at% as compared to Ga at% in the bulk of the films, it is worth mentioning that the N at% is overestimated due to the significant contribution of the Ga Auger peak, which overlaps with the N 1s peak. 21,30 In concentrations obtained from the surface for In x Ga 1Àx N thin films with RS of 0.5, 0.75, and 0.83 are calculated to be 0.11, 0.17, and 0.19, respectively, which are significantly lower than the values obtained using Vegard's law. Possible inhomogeneous distribution of In and Ga atoms in the vicinity of the surface of In x Ga 1Àx N samples might explain the lower In surface concentration.…”

“…Possible inhomogeneous distribution of In and Ga atoms in the vicinity of the surface of In x Ga 1Àx N samples might explain the lower In surface concentration. 30,31 In addition, overestimation of the nitrogen surface contents as explained previously can implicate lowering of In concentration. In x Ga 1Àx N thin films with RS of 0.5, 0.75, and 0.83 exhibited In concentrations of 0.07, 0.09, and 0.13 from the bulk of the films, respectively.…”

Growth of Amorphous InGaN Films on Si for Potential Photovoltaic Application

“…To study the surface chemical states of deposited InGaN films, high-resolution XPS scans were performed on In-3d, Ga-3d, N-1 s, and O-1 s, and the assignments of photoelectron peaks to various chemical states are given in Table 2. The In-3d 5/2 peak is assigned to three chemical states: metallic In at 444.8 eV [15], In bonded to O as the oxide In 2 O 3 at 444.3 eV [16] and 444.9 eV [17], and N with In bonded O as the complex compound InN x O y at 445.6 eV [18]. The presence of metallic In at 125 mJ/pulse shows an inhomogeneous In distribution on the surface.…”

“…At 175 mJ/pulse, metallic Ga is either not detected due to the higher energy of incident particles. For N-1 s peak, the binding energies located at 399.2 eV, 398.0 eV, 396.5 eV and 395.8 eV can be respectively assigned to N bonded to O (NO 3 ) [18], N bonded to Ga (GaN) [23], N bonded to In (InN) and an uncertain peak (395.8 eV) [24]. The O-1 s peak is assigned to four chemical states: O bonded to Ga (Ga 2 O 3 ) at 529.8 [25], O bonded to In (In 2 O 3 ) or Ga (Ga x O y ) at 530.5 eV and O bonded to N (NO 3 ) at 532.4 eV [18].…”

Composition measurement of epitaxial ScxGa1−xN films

“…The samples were grown using metal-rich conditions and therefore a metal-rich surface layer is expected to be present. A Ga-enriched surface would produce a lower Sc content as measured by XPS [45]. Additionally, ion sputtering is expected to remove the Sc and N faster than Ga from the surface (the bond energy of ScN 6.72 eV/atom [46] is lower than that of GaN 8.92 eV/atom [47,48], therefore a relatively greater sputtering rate for Sc atoms is expected compared to Ga atoms).…”