PURPOSE: To provide high heat resistance, excellent reproducibility and characteristic stability by employing nitrided titanium having excellent diffusion preventing effect as a diffusion barrier layer.

CONSTITUTION: In the function of each layer forming electrode, a layer 3 is a titanium itself or a contact layer for forming an ohmic contact or Schottky barrier with good reproducibility of titanium arsenide compound formed by heat treatment, a nitrided titanium layer 4 is a diffusion barrier layer for preventing the production of compound such as a platinum and arsenic, platinum and gallium or the like, a platinum layer 5 is an intermediate layer to be inserted to enhance the contact layer to the layer 4 of a gold layer 6, and the layer 6 is a conductor. In this manner, a diffusion barrier layer due to nitrided titanium is filled, thereby preventing the mutual reaction of the electrode metal and the semiconductor except the titanium, enhancing the heat resistance, and providing excellent characteristic reproducibility and stability.