Abstract
Double buffer layers composed of (Al(x)Ga(1-x))(2)O(3)/Ga(2)O(3) structures were employed to grow a Sn-doped α-Ga(2)O(3) epitaxial thin film on a sapphire substrate using mist chemical vapor deposition. The insertion of double buffer layers improved the crystal quality of the upper-grown Sn-doped α-Ga(2)O(3) thin films by blocking dislocation generated by the substrates. Rapid thermal annealing was conducted for the double buffer layers at phase transition temperatures of 700-800 °C. The slight mixing of κ and β phases further improved the crystallinity of the grown Sn-Ga(2)O(3) thin film through local lateral overgrowth. The electron mobility of the Sn-Ga(2)O(3) thin films was also significantly improved due to the smoothened interface and the diffusion of Al. Therefore, rapid thermal annealing with the double buffer layer proved advantageous in achieving strong electrical properties for Ga(2)O(3) semiconductor devices within a shorter processing time.