Method for manufacturing fin transistor that prevents etching loss of a spin-on-glass insulation layer

Abstract

A method for manufacturing a fin transistor includes forming a trench by etching a semiconductor substrate. A flowable insulation layer is filled in the trench to form a field insulation layer defining an active region. The portion of the flowable insulation layer coming into contact with a gate forming region is etched so as to protrude the gate forming region in the active region. A protective layer over the semiconductor substrate is formed to fill the portion of the etched flowable insulation layer. The portion of the protective layer formed over the active region is removed to expose the active region of the semiconductor substrate. The exposed active region of the semiconductor substrate is cleaned. The protective layer remaining on the portion of the etched flowable insulation layer is removed. Gates are formed over the protruded gate forming regions in the active region.