Semi-conductor device with stacked trench capacitor

Claim 1

A semiconductor device, comprising: a field oxide layer selectively formed to define an active region on a semiconductor substrate of a first conductivity type; a gate electrode of the first conductive layer electrically insulated on said active region; a source region and a drain region of a second conductivity type formed on the surface of said semiconductor substrate and at both sides of said gate electrode; a trench formed in said semiconductor substrate within said source region; an impurity-doped region of said second conductivity type formed at the surface of said trench to be connected to said source region; a first insulating layer for insulating said first conductive layer; a second conductive layer formed to be connected to said impurity-doped region through a part of said source region on said first insulating layer; a dielectric film formed on both said second conductive layer and the inside of said trench including said impurity-doped region; a third conductive layer formed on said dielectric film to fill said trench; an etch blocking layer formed on said third conductive layer and a fourth conductive layer formed on said etch blocking layer, said etch blocking layer being used in an etch back process for forming said fourth conductive layer, and both said etch blocking layer and said fourth conductive layer being formed at a center portion of said trench, thereby removing the voids produced in the interior of said trench; and a fifth conductive layer formed to cover said third conductive layer and said fourth conductive layer such that said fourth conductive layer is electrically connected to said third conductive layer via said fifth conductive layer.