Patent ID: 7687355

Claim:
A method for manufacturing a fin transistor, comprising the steps of: forming a trench by etching a semiconductor substrate; filling a flowable insulation layer in the trench to form a field insulation layer defining an active region; etching a portion of the flowable insulation layer coming into contact with a gate forming region so as to protrude the gate forming region in the active region; forming a protective layer over the semiconductor substrate to fill the etched portion of the flowable insulation layer removing a portion of the protective layer formed over the active region to expose the active region of the semiconductor substrate; cleaning the exposed active region of the semiconductor substrate, the protective layer, which remains after exposing the active region, being formed so as to prevent removal of a side of the etched portion of the flowable insulation layer during the cleaning; removing the protective layer remaining on the etched portion of the flowable insulation layer after the cleaning of the exposed active region; and forming gates over the protruded gate forming regions in the active region.