Oxygen-radical-assisted pulsed-laser deposition of β-Ga2O3 and β-(AlxGa1−x)2O3 films.

We report on impacts of oxygen-radical (O ⁎ ) atmosphere for pulsed-laser deposition (PLD) of β -Ga 2 O 3 and β -(Al x Ga 1− x ) 2 O 3 films on (010) β -Ga 2 O 3 substrate in comparison with conventional PLD in O 2 atmosphere. Severe sublimation of Ga species arising from insufficient oxidation in the O 2 atmosphere resulted in substantial decrease in growth rate of the homoepitaxial films and condensation of Al content in the (Al x Ga 1− x ) 2 O 3 films. In the case of O ⁎ -assisted PLD, it was found that the growth rate of homoepitaxial films greatly recovered, and the Al content remained nearly identical to that in the target. Moreover, the use of O ⁎ allowed to reduce surface roughness of homoepitaxial films. These results indicate that O ⁎ -assisted PLD is a powerful tool for fabricating β -Ga 2 O 3 -based heterostructures. [ABSTRACT FROM AUTHOR]