The present disclosure relates a Fin field effect transistor (FinFET) device having large effective oxide thickness that mitigates hot carrier injection, and an associated method of formation. In some embodiments, the FinFET device has a conductive channel of a first fin protruding from a planar substrate. The conductive channel has a non-conductive highly doped region located along multiple outer edges of the channel region. A gate region protrudes from the planar substrate as a second fin that overlies the first fin. A gate dielectric region is located between the non-conductive highly doped region and the gate region. The non-conductive highly doped region and the gate dielectric region collectively provide for an effective oxide thickness of the FinFET device that allow a low electric field across gate oxide and less hot carrier injection.