2 research outputs found
Growth, catalysis and faceting of -GaO and -(InGa)O on -plane -AlO by molecular beam epitaxy
The growth of -GaO and -(InGa)O
on -plane -AlO(100) by molecular beam epitaxy (MBE)
and metal-oxide-catalyzed epitaxy (MOCATAXY) is investigated. By systematically
exploring the parameter space accessed by MBE and MOCATAXY, phase-pure
-GaO(100) and
-(InGa)O(100) thin films are realized. The
presence of In on the -GaO growth surface remarkably expands
its growth window far into the metal-rich flux regime and to higher growth
temperatures. With increasing O-to-Ga flux ratio (), In
incorporates into -(InGa)O up to .
Upon a critical thickness, -(InGa)O nucleates and
subsequently heteroepitaxially grows on top of
-(InGa)O facets. Metal-rich MOCATAXY growth
conditions, where -GaO would not conventionally stabilize, lead
to single-crystalline -GaO with negligible In incorporation and
improved surface morphology. Higher further results in
single-crystalline -GaO with well-defined terraces and step
edges at their surfaces. For , In acts as a surfactant
on the -GaO growth surface by favoring step edges, while for
, In incorporates and leads to a-plane
-(InGa)O faceting and the subsequent (01)
-(InGa)O growth on top. Thin film analysis by STEM
reveals highly crystalline -GaO layers and interfaces. We
provide a phase diagram to guide the MBE and MOCATAXY growth of
single-crystalline -GaO on -AlO(100)
Growth of β-Ga2O3 and ϵ/κ-Ga2O3 on AlN(0001) by molecular-beam epitaxy
The heteroepitaxial growth and phase formation of Ga2O3 on Al-polar AlN(0001) templates by molecular-beam epitaxy (MBE) are studied. Three different MBE approaches are employed: (i) conventional MBE, (ii) suboxide MBE (S-MBE), and (iii) metal-oxide-catalyzed epitaxy (MOCATAXY). We grow phase-pure β-Ga2O3(2̄01) and phase-pure ϵ/κ-Ga2O3(001) with smooth surfaces by S-MBE and MOCATAXY. Thin film analysis shows that the crystallographic and surface features of the β-Ga2O3(2̄01)/AlN(0001) and ϵ/κ-Ga2O3(001)/AlN(0001) epilayers are of high crystalline quality. Growth and phase diagrams are developed to synthesize Ga2O3 on AlN by MBE and MOCATAXY and to provide guidance to grow Ga2O3 on several non-oxide surfaces, e.g., AlN, GaN, and SiC, by MBE, S-MBE, and MOCATAXY