Semiconductor device and method of fabricating the same

A method of fabricating a transistor of a semiconductor device, the method comprising:

• forming first and second trenches for gates in a substrate, wherein the trenches are spaced apart from each other by a predetermined distance;
• forming a liner layer on innerwalls of the first and second trenches;
• forming first and second epitaxial gate electrodes by performing a selective epitaxial growth on the first and second trenches comprising the liner layers therein;
• forming isolation structures in the substrate, wherein the isolation structures are formed to contact the first and second epitaxial gate electrodes, respectively;
• forming a gate insulation layer and a gate electrode over a region of the substrate between the first and second epitaxial gate electrodes;
• and
• forming source and drain regions in the substrate disposed in respective edge regions of the gate electrode and overlapping the gate electrode.