Disclosed are a transistor and a method for fabricating the same capable of increasing a threshold voltage and a driving current of the transistor. The method includes the steps of forming a first etch mask on a silicon substrate, forming a trench by etching the exposed isolation area, forming a first insulation layer in the trench and the first etch mask, forming a second insulation layer on the first insulation layer, removing the second insulation layer and the first insulation layer until the first etch mask is exposed, forming a trench type isolation layer on the isolation area, forming a second etch mask on an entire surface of the silicon substrate, etching the exposed channel area, performing an etching process with respect to a resultant substrate structure, and forming a gate in the recess.