Nitride based semiconductor device and method for manufacturing the same

A nitride based semiconductor device comprising:

• a base substrate;
• an epitaxial growth layer disposed on the base substrate and generating a 2-dimensional electron gas in an inner portion thereof;
• and
• an electrode structure disposed on the epitaxial growth layer,
• wherein the electrode structure includes:
• a gate electrode;
• a source electrode disposed at one side of the gate electrode;
• and
• a drain electrode disposed at the other side of the gate electrode and having an extension part extended to the inner portion of the epitaxial growth layer to contact the 2-dimensional electron gas, wherein:
• the drain electrode is a first Schottky electrode forming a first Schottky contact with the epitaxial growth layer,
• the gate electrode includes a second Schottky electrode forming a second Schottky contact with the epitaxial growth layer,
• the source electrode includes an ohmic electrode forming an ohmic contact with the epitaxial growth layer,
• the epitaxial growth layer includes:
• a lower nitride layer grown using the base substrate as a seed layer;
• and
• an upper nitride layer grown using the lower nitride layer as a seed layer and having a wider energy band gap than that of the lower nitride layer, and
• the extension part extends to an upper part of the lower nitride layer so that the extension part is not contacted to the base substrate.