A novel lateral power fin metal-oxide-semiconductor field-effect transistor (MOSFET) made on a silicon-on-insulator substrate is proposed. The fin silicon drift region of the proposed device is surrounded by a high-k (HK) passivation. The HK passivation enables the proposed device to realize a three-dimensional (3D) enhanced reduced-surface-field action and a 3D accumulation layer. According to the simulation results, when compared to a lateral power planar MOSFET with an HK passivation, the proposed device offers a 78% reduction in specific on-resistance at the same 100-V breakdown voltage. More comparative studies indicate that the static characteristic of the proposed device not only overcomes the silicon limit but also presents a significant advantage when compared to the prior art.