Abstract: In a high-breakdown-voltage diode, a high-concentration p-type layer is selectively formed in an n-type silicon layer, and a high-concentration n-type layer is formed in the same separate from the layer by a predetermined distance. An insulation film having a dielectric constant larger than silicon is formed on that portion of the n-type silicon layer which extends between the layers, for relaxing concentration of an electric field caused in the surface of the substrate.

Abstract: Heterostructure metal insulator semiconductor integrated circuit technology resulting in, for instance, GaAs field-effect-transistors having much less gate current leakage and greater voltage range than like technology of the related art.

Abstract: On an insulating layer (32) formed on a metal substrate (31), cascode-connected power switching elements (1-6) are provided and shield patterns (101-104) are formed. Control circuits (13-18) for the switching elements (1-6) are formed on insulating layers (105, 106) formed on the shield patterns (101-104) which are fixed to potentials responsive to potentials of output electrodes of the corresponding switching elements (1-6). The control circuits (13-18) and the corresponding shield patterns (101-104) are in capacity coupling. Thus, noise arises in the control circuits (13-18) with respect to the metal substrate (31) when noise is applied to current paths of the switching elements (1-6) with respect to the metal substrate (31). As a result, viewing from the output electrodes of the switching elements (1-6), the control circuits (13-18) have noise equivalent to nothing.