Production manner null of n die GaAs and the ohmic electrode for n die GaAlAs

摘要

PURPOSE:To reduce thermal influence given to a semiconductor element by forming the electrode from Au, Ge, Cr. CONSTITUTION:This electrode is formed of Au, Ge, Cr. For example, a Cr layer 2 of 100Angstrom thick, a Ge layer 3 of 200Angstrom thick, an Au layer 4 of 3000Angstrom are sequentially laminated on a substrate 1 made of n type GaAs of 2*101e/cm3 of carrier density, heat treated and formed as n type side electrode. A natural oxide film in which Cr is formed on the surface of n type GaAs or n type GaAlAs surface is reduced to aid to diffuse Ge into n type GaAs or n type GaAlAs. Thus, even if alloying temperature is 250 deg.C or lower, sufficient ohmic contact is obtained. Accordingly, thermal influence to a semiconductor element at alloying time can be reduced as compared with the conventional one.