PURPOSE: To simply and easily form RHET or RTB, different from each other in peak voltage VP and valley voltage VV, on one substrate, and thereby make it possible to select optimum one from among these elements to constitute a circuit.

CONSTITUTION: A collector layer 43, a base layer 45, an emitter layer 47 and so on are formed on a substrate 41. An emitter electrode 49L of ohmic contact and that 49H of Schottky contact are formed thereon, and thus a first RHET 40L and a second RHET 40H, different from each other in peak voltage VP and valley voltage VV, are incorporated. These elements are selected as required for the formation of a logical circuit.