A. V. Almaev

HVPE growth of corundum-structured $α$-Ga$_2$O$_3$ on sapphire substrates with $α$-Cr$_2$O$_3$ buffer layer

Gallium oxide films were grown by HVPE on (0001) sapphire substrates with and without $α$-Cr$_2$O$_3$ buffer produced by RF magnetron sputtering. Deposition on bare sapphire substrates resulted in a mixture of $α$-Ga$_2$O$_3$ and $ε$-Ga$_2$O$_3$ phases with a dislocation density of about $2\cdot10^{10}$ cm$^{-2}$. The insertion of $α$-Ga$_2$O$_3$ buffer layers resulted in phase-pure $α$-Ga$_2$O$_3$ films and a fourfold reduction of the dislocation density to $5 \cdot 10^9$ cm$^{-2}$.