Method for fabricating semiconductor device

Abstract

A method for fabricating a semiconductor device includes the steps of forming a field oxide layer on a first conductivity-type semiconductor substrate, and forming a pattern of first active regions. The field oxide layer is selectively removed between the first active regions to pattern a second active region and word lines are formed substantially perpendicular to each of the first active regions. A second conductivity-type impurity is implanted into the substrate using a mask to form impurity diffusion regions in the first and second active regions. A first insulating layer is formed over an overall surface of the substrate, and forming a first contact hole in the second active region. A bit line is formed for contacting with the impurity diffusion region on the second active region through the first contact hole. A second insulating layer is formed over the first insulating layer and the bit line, and the second impurity layer is selectively removed to form second contact holes on portions of the first active regions, respectively.