Formation of metallic electrode

PURPOSE: To provide a technique to form fine metallic films with good controllability on a compound semiconductor layer such as GaAs or the like. CONSTITUTION: After a protection film 102 of single atom layer level mainly consisting of S is formed on a GaAs layer 101, a part of the protection film 102 is selectively removed by irradiation of a focused energy beam, for example, an ion beam 103 to leave the protection film 102 only in the desired fine region. Next, a W film 104 is deposited only on the protection film 102 of the fine region by application of selective CVD technique of a metal, for example, W. Thereby, controllability within a fine region such as a line width of an energy beam, for example, ion beam 103 focused on the GaAs layer 101. COPYRIGHT: (C)1993,JPO&Japio