Field-induced current modulation in epitaxial film of deep-ultraviolet transparent oxide semiconductor $Ga2O3$

Epitaxial films of a deep-ultraviolet transparent oxide semiconductor, $Ga2O3$⁠, were fabricated on $α-Al2O3$ (0001) substrates by pulsed laser deposition. Four-axes x-ray diffraction measurements revealed that the tin-doped $Ga2O3$ films have a crystal structure different from any known polymorphs of $Ga2O3$⁠. Its crystal lattice was determined to be an orthorhombic. Top gate field-effect transistor structures were fabricated using the $Ga2O3$ epitaxial films for $n$-channels. The channel conductance was modulated by an order of magnitude by gate voltage at room temperature with an estimated field-effect mobility of $5×10−2cm2(Vs)−1$⁠.