Provided is a capacitor-less DRAM device including: an insulating layer formed on a semiconductor substrate; a silicon layer formed on the insulating layer, wherein a trench is formed inside the silicon layer; and an offset spacer formed on both sidewalls of the trench and protruded upward through the silicon layer. A gate insulating layer is formed on a bottom of the trench, and a gate electrode is formed to be buried in the gate insulating layer and in the trench and the offset spacer. A source region and a drain region are formed in the silicon layer on both sides of the offset spacer so as not to overlap with the gate electrode. A channel region is formed in the silicon layer below the gate insulating layer to be self-aligned with the gate electrode.