| 摘要 |
PROBLEM TO BE SOLVED: To form a metal electrode which displays ohmic characteristics by a method wherein the metal electrode is equipped with a first layer that contains at least Ga and N as component elements, a metal film, and an interposition layer that contains at least one of elements such as S, Se, Te, As, P, and Hf and is interposed between the first layer and the metal film. SOLUTION: The surface of a GaN layer is etched by the use of an HF solution to remove an oxide film from it, residual F is removed, an interposition layer 12 is formed, and then a metal electrode is evaporated for the formation of a metal electrode 3 that displays complete ohmic characteristics. F atoms as etching contaminants are removed, whereby only a surface level caused by a surface condition that is naturally present on the surface of a GaN crystal is left on the surface of a contact layer 2, so that a pinning effect is slightly relaxed, but as a crystal has its own intrinsic surface state, the pinning effect cannot be completely removed only by cleaning. Therefore, when Se, Te, As, P, or Hf is used as a terminal atom besides O, a metal electrode that displays perfect ohmic characteristics can be formed.
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