Electrical Properties Of Exfoliated Gallium Oxide Field Effect Transistor

Gallium Oxide material is a new generation of semiconductor material,which has the characteristics of wide bandgap and high breakdown electric field.Strictly speaking,gallium oxide is not a new kind of material.Early research on gallium oxide can be traced back to the 1950 s and 1960 s.For half a century,the research on gallium oxide has never stopped.In recent years,with the breakthrough of Gallium Oxide single crystal growth technology and the maturation of epitaxy technology,Gallium Oxide materials have attracted more and more attention.In 2014,a method of fabricating field effect transistors(FETs)by mechanical stripping was discovered.Gallium Oxide FETs based on mechanical stripping showed great potential and important role.In this paper,the technology of mechanical stripping of gallium oxide is studied.Three methods of transferring the stripped sheets to heterogeneous substrates are explored.A backgate field effect transistor based on mechanical stripping of gallium oxide sheets is fabricated.In the transfer characteristic curve of the device,the threshold voltage changes obviously with the change of the measurement starting voltage.In the process of reciprocating measurement,obvious hysteretic characteristics are observed.In the measurement of-40 V ~ 40 V,the device is usually open,while in the measurement of 40 V ~ 40 V,the device is depleted,and the threshold voltage drift is as high as 40 V.During the measurement of output characteristics,the DC current-voltage characteristic curve is obtained under high leakage voltage when the gate is suspended,which shows obvious phenomenon of saturated current instability and secondary jump.Based on the previous research,it is considered that the reason for this phenomenon is that the physical contact interface between Ga2O3 and SiO2 is not close enough to absorb water and oxygen in the air to form a charge-holding layer,which results in the drift of threshold voltage and the instability of current-voltage curve and secondary jump under high voltage.