Progress in MOVPE growth of Ga2O3

The metalorganic vapor-phase epitaxy (MOVPE) of gallium oxide is reviewed. It is shown that different Ga2O3 phases can be prepared by tuning the epitaxial growth parameters. The deposition temperature, partial pressure of the precursors, and crystallographic structure of the starting substrate/template are crucial in providing ?, ?, ?, and ? polymorph. At high deposition temperature (> 700°C), only the ?-phase can be obtained, while at lower temperatures, the growth of the other metastable phases becomes possible. This chapter reviews the status of homoepitaxial and heteroepitaxial ?-Ga2O3 as well as the heteroepitaxial growth of the orthorhombic "pseudo-hexagonal" ?-phase. It is shown that although metastable, ?-Ga2O3 may be grown with very good crystallographic properties on different hexagonal substrates.