Patent ID: 8896028

Claim:
A semiconductor device comprising: an epitaxial substrate formed by stacking a plurality of kinds of semiconductors over one semiconductor substrate by epitaxial growth; a field effect transistor of a first conductivity type formed in a first region of the epitaxial substrate by utilizing a stacking structure of the epitaxial substrate; a field effect transistor of a second conductivity type formed in a second region different from the first region of the epitaxial substrate by utilizing a stacking structure of the epitaxial substrate; and a protective element formed in a third region different from the first region and the second region of the epitaxial substrate by utilizing a stacking structure of the epitaxial substrate, wherein the protective element includes a first stacking structure formed by etching the epitaxial substrate by vertical etching that proceeds in a stacking thickness direction, and a second stacking structure formed by etching the epitaxial substrate by vertical etching that proceeds in a stacking thickness direction, and the protective element has two PN junctions on a current path formed between an upper end of the first stacking structure and an upper end of the second stacking structure via a base part of the first stacking structure and the second stacking structure.