$\alpha$-Cr$_2$O$_3$ layers grown on (100) $\beta$-Ga$_2$O$_3$ substrates by ultrasonic vapor chemical epitaxy (mist-CVD)

Heterocontacts based on $\alpha$-Cr$_2$O$_3$/$\beta$-Ga$_2$O$_3$ have recently aroused interest, as they make it possible to realize the potential of gallium oxide, an ultra-wide-band semiconductor in instrument structures, since the latter has no prospects yet in obtaining p-type conductivity samples with parameters suitable for instrument applications. While for $\alpha$-Cr$_2$O$_3$ it is quite achievable. In this work, for the first time, epitaxial chromium oxide layers on bulk gallium oxide substrates with a thickness of up to 1 micron or more were obtained by the CVD method. The question of the orientation of these layers is investigated. X-ray diffraction revealed that the $\alpha$-Cr$_2$O$_3$ layers grown on (100) $\beta$-Ga$_2$O$_3$ plates have a single layer reflex corresponding to $(11\bar 26)$.