Fabrication of ultrathin(sub-6 nm) Sn doped amorphous gallium oxide field effect transistor with enhanced mobility

Abstract

Gallium oxide(Ga$_2$O$_3$) can be applied to wide range of applications as a semiconductor. In case of gas sensor, surface to volume ratio must be large to get higher gas sensing ability, which means thinner gallium oxide(Ga$_2$O$_3$) is needed. Also, flat panel display needs thin gallium oxide(Ga$_2$O$_3$) and for flexible flat panel display, amorphous phase gallium oxide(Ga$_2$O$_3$) is needed. In this thesis, ultrathin(sub-6 nm) amorphous gallium oxide(Ga$_2$O$_3$) film is deposited by using RF magnetron sputtering, followed by Sn doping to increase n type semiconductivity. Using this ultrathin(sub-6 nm) Sn doped amorphous gallium oxide(Ga$_2$O$_3$) film, field effect transistor is fabricated. Hydrogen annealing has been used to achieve comparable mobility with thicker gallium oxide(Ga$_2$O$_3$) films. In addition, hydrogen annealing is processed to improve mobility of the transistor. As a result, amorphous gallium oxide(Ga$_2$O$_3$) field effect transistor could achieve enhanced mobility(~ 0.6 cm$^2$/Vs).