The present invention relates to a field-effect transistor manufacturing method and relates to a structure, specifically, the bi-layer structure with fin field effect transistor manufacturing method and the manufacturing method with the bi-layer structure produced by a fin field effect transistor CMOS inverter. The method of forming a fin field effect transistor as a bi-layer structure according to the present invention, (a) a substrate, comprising: a pin-channel structure on the substrate, forming a silicon layer to be formed; (B) implanting oxygen ions into the entire surface of the silicon layer to form an oxygen ion implanted layer inside the silicon layer; (C) a step of heat-treating the oxygen ion implanted layer in an oxygen atmosphere to form a buried oxide layer electrically isolated from the upper layer and the lower layer of the silicon layer is insulated from the silicon layer; (D) etching the silicon layer by anisotropic plasma bulk form an active area of ​​the fin channel structure; (E) forming a gate by depositing and etching the gate material on the same substrate; And (f) a lower layer transistor for the source and the ion to form a drain wherein the selectively implanted into the silicon layer portion of the lower layer a lower layer transistor forming, and an upper layer transistor for the source and the ion to form the drain the upper layer of the silicon layer selective implantation with the part to be characterized in that it comprises the step of forming the upper layer transistor. Oxygen implantation separation method (SIMOX), fin field effect transistor (FinFET), short channel effect (Short Channel Effects), the inverter (Inverter), a double gate (Double Gate), a trench, a three-dimensional structure of the transistor, the vertical integrated (Vertical Integration)