Improved Phase Stability of Orthorhombic κ-Ga₂O₃ Grown by Mist CVD

β-Ga₂O₃ is attractive for high-power applications because it has a large bandgap (&gt; 4.5 eV) and a high breakdown field (~ 8 MV/cm). But more importantly, the thermodynamically stable β-Ga₂O₃ (monoclinic) can be grown as a single crystal substrate for homoepitaxial devices with very low dislocation density (&lt; 10⁴ cm^-2). Other meta-stable phases such as α (corundum) and κ (orthorhombic) with unique properties of their own have drawn a lot of interest lately. The orthorhombic κ-phase is especially interesting as it is known to be ferroelectric and has a large spontaneous polarization, possibly an order of magnitude higher than that of III-V semiconductors such as GaN and AlN. Therefore, κ-Ga₂O₃ can be combined with III-Nitrides or (Al_xGa_1-x)₂O₃ for a high electron-mobility transistor (HEMT) with a sheet carrier density higher than 10¹² cm^-2.<br/>Meta-stable κ-Ga₂O₃can be grown on different substrates such as (0001) sapphire (rhombohedral), (0001) GaN, 6H-SiC (hexagonal), (111) yttria-stabilized zirconia, and MgO (cubic). κ-Ga₂O₃ shows some degree of rotational domains on all of these substrates. Phase control of κ-Ga₂O₃ on these substrates relies on an intricate balance among the epitaxial relation, lattice mismatch, and growth kinetics (i.e. growth temperature). For κ-Ga₂O₃ to be a viable option for a high-power HEMT, these material issues need to addressed. In this presentation, we will report on the Sn-induced phase stabilization and its impact on the thermal stability of κ-Ga₂O₃ grown by mist chemical vapor deposition (CVD). We will also discuss the growth of κ-Ga₂O₃on different substrates and the impacts on the rotational domains.