[11a-S011-1~9] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[11a-S011-5] Low temperature transport property for the beta-Ga₂O₃ single crystals

〇Yasuhide Tomioka¹, Yasuko Ozaki¹, Hideki Inaba¹, Toshimitsu Ito¹ (1.AIST)

Keywords:Floating Zone method, beta-Ga2O3, power devices

We have investigated the transport properties in the Si-doped beta-Ga₂O₃ single crystals prepared by the floating zone method. The resistivity and Hall effect have been measured for the Si-doped beta-Ga₂O₃ crystals with various conduction electron densities (n). For the crystals with the relatively lower n, the resistivity is metallic at higher temperatures while it becomes semiconducting below ~150 K. With a further decrease in temperature, a shoulder or plateau-like structure is seen in the resistivity as a function of the reciprocal temperature, and correspondingly the Hall coefficient (-R_H) exhibits maximum. In the p-type germanium or antimony-doped germanium in which the doped acceptors are partly compensated by donors, the phenomena have been well known as the impurity conduction. It is suggested from this study that the present beta-Ga₂O₃ crystals also exhibit the impurity conduction due to the compensation of donors by possible acceptors.