The application provides a
semiconductor device and a manufacturing method thereof, and the
semiconductor device comprises a substrate, a first
gallium oxide bulk layer on the substrate, a
gallium oxide epitaxial layer on the first
gallium oxide bulk layer, wherein the
gallium oxide epitaxial layer comprises a plurality of stacked structures, each of the stacked structures comprises a
silicon-doped
gallium oxide layer and a non-
silicon-doped
gallium oxide layer which are stacked, and a second gallium oxide bulk layer on the gallium oxide epitaxial layer. The gallium oxide epitaxial layer of the application comprises a plurality of stacked structures, each of the stacked structures comprises a
silicon-doped gallium oxide layer and a non-silicon-doped gallium oxide layer which are stacked, and the gallium oxide bulk
layers are respectively formed in front of and behind the gallium oxide epitaxial layer, so that the
electron mobility of the gallium oxide epitaxial layer can be effectively improved, the
doping efficiency is improved, the
crystal quality of the gallium oxide epitaxial layer is improved, and the gallium oxide epitaxial layer is widely applied in the field of power devices.