Semiconductor device and a method for manufacturing the same

A method for manufacturing a semiconductor device, the method comprising:

• providing a substrate in which an insulation layer is disposed between a first semiconductor layer and a second semiconductor layer;
• etching the second semiconductor layer to form a first hole that exposes the insulation layer;
• etching the exposed insulation layer to form a second hole that extends into the first semiconductor layer;
• growing an epi-layer on a bottom surface of the second hole;
• forming a source electrode and a gate electrode on a top surface of the epi-layer;
• etching the first semiconductor layer to form a third hole that is connected to the second hole;
• and
• forming a drain electrode that extends from one surface of the first semiconductor layer into the third hole and contacts the epi-layer.