Method of Manufacturing Semiconductor Device and the Semiconductor Device

A method of manufacturing a semiconductor device that includes a gate oxide film, which is formed on a surface of a semiconductor substrate;

• a main electrode, which is formed on the surface and a current flowing through which is switched by a voltage applied to a gate electrode formed on the gate oxide film;
• and a silicide electrode is provided between the main electrode and the surface, the method comprising:
• forming, sequentially, a gate electrode material layer made of a material configuring the gate electrode and a barrier material layer made of a silicon nitride film, on the gate oxide film;
• forming an upper barrier layer configured to an upper surface of the gate electrode with the barrier material layer and forming the gate electrode from the gate electrode material later by etching the barrier material layer and the gate electrode material layer with a same mask pattern;
• forming a sidewall barrier layer configured to cover a side surface of the gate electrode by forming again the barrier material layer after the forming of the gate electrode from the gate electrode material later;
• forming an interlayer insulation layer configured to cover a surface-side of the semiconductor substrate including the upper surface barrier layer and the sidewall barrier layer;
• and
• opening the interlayer insulation layer and then forming the silicide electrode on the surface of the semiconductor substrate.