As a promising ultra-wide-bandgap semiconductor for high power devices, ?-Ga2O3 is under broad research owning to its high breakdown field and melt-grown substrates availability. The lateral ?-Ga2O3 power devices have received lots of attraction due to high-speed operation. In this work, the ?-Ga2O3 lateral power devices have been researched from MOSFETs to FinFETs for superior performance. The threshold voltage modulation by fin width in β-Ga2O3 lateral fin transistors was demonstrated for the first time. Moreover, the advantage of fin geometry in mitigating the high interface trap density on the top surface of (0 1 0) β-Ga2O3 was also shown in this research. Besides, the ?-Ga2O3 fin dry etching has been studied to optimize the FinFET performance. Factors impacting the fin waist narrowing, including the thermal paste, in fin waist narrowing of ?-Ga2O3 dry etching were discussed for the first time.