A new MOSFET structure, which has $n^{+}$ poly-silicon floating side gates and main gate with mid-gap work function, is proposed. Inversion layer is easily induced below the floating side gates due to the low doping concentration and acts as extended source/drain regions. By applying indium halo doping, short-channel effect is suppressed while keeping relatively low channel doping concentration which leads to higher channel mobility and lower threshold voltage fluctuation due to random dopant. Device design is successfully done down to 20-nm regime by extensive simulation and excellent device characteristics are obtained. And the application of the proposed structure is presented.