Rutile- and anatase-phase Nb-doped TiO2 (TiO2:Nb) epilayers were selectively grown on a GaN template by the helicon-wave-excited-plasma sputtering epitaxy (HWPSE) method. The rutile (100) TiO2:Nb films grew on the etched clean (0001) GaN surface with the in-plane epitaxial relationship  TiO2 // [10-10] GaN, regardless of growth temperature. While, the anatase (001) TiO2:Nb films grew on appropriately oxidized (0001) GaN with the in-plane relations  TiO2 // [10-10] GaN (and  TiO2 // [11-20] GaN) under high temperature and low oxygen partial pressure conditions. The lowest resistivity of the heterostructure was 3×10-4 Ω·cm. The selective growth of anatase films is assigned as being due to the formation of a sheet of Ga-O layer, possibly (001) or (100) orientation β-Ga2O3, on the GaN surface.
|Number of pages||3|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 2011 Feb|
- Anatase TiO
- Titanium dioxide