Abstract: In the structure of a semiconductor device of the present invention, a first source electrode is connected to a conductive substrate through a via hole, and a second source electrode is formed. Thus, even if a high reverse voltage is applied between a gate electrode and a drain electrode, electric field concentration likely to occur at an edge of the gate electrode closer to the drain electrode can be effectively dispersed or relaxed. Moreover, the conductive substrate is used as a substrate for forming element formation layers, so that a via hole penetrating the substrate to reach the backside thereof does not have to be formed in the conductive substrate. Thus, with the strength necessary for the conductive substrate maintained, the first source electrode can be electrically connected to a backside electrode.

Abstract: The present invention, which aims at providing a semiconductor switch capable of reducing harmonic distortion, is made up of: an input terminal 101; an output terminal 102; a through FET 106 that is connected serially to the signal path between the input terminal 101 and the output terminal 102; a shunt FET 107 that is connected in between the output terminal 102 and the ground; and a distortion reducing circuit 120 that is connected in parallel with the through FET 106. In this semiconductor switch, the distortion reducing circuit 120 includes: a first diode 109 and a second diode 110 that are placed in parallel with each other; a first constant voltage source 111 and a second constant voltage source 112 that are placed in parallel with each other; and a FET 108.

Abstract: A field-effect transistor includes: a carrier supply layer supplying carriers; a Schottky contact layer forming a Schottky barrier; and an intermediate layer formed between the carrier supply layer and the Schottky contact layer. Here, the intermediate layer has an electron affinity which is higher than an electron affinity of the carrier supply layer but lower than an electron affinity of the Schottky contact layer.

Abstract: A method of forming films in a semiconductor device that can appropriately control a resistance value of a thin film resistance on an ozone TEOS film while preventing a metal thin film from remaining around a surface step unit after the metal thin film was dry etched. First, as shown in FIG. 1A, a step unit with the height of about 1 &mgr;m is formed by forming elements such as HBT on a semiconductor substrate made up of semi-insulating GaAs. Next, as shown in FIG. 1B, a first ozone TEOS film with the thickness of 900 nm by a Normal pressure CVD method using mixed gas of tetraethoxysilane with ozone. Then, a second ozone TEOS film with the thickness of 100 nm is formed by reducing the ozone concentration to 10 g/m3, while maintaining the substrate temperature at 350° C.

Abstract: A compound semiconductor device includes an emitter layer, a base layer which is in contact with the emitter layer and formed of a first compound semiconductor, a collector layer which is in contact with the base layer and formed of a second compound semiconductor having a wider bandgap than that of the first compound semiconductor. In the device, a delta doped layer having a higher concentration of an impurity than that of the collector layer is formed at the heterojunction interface between the collector layer and the base layer or in a region of the collector layer located at about 10 nm or less from the heterojunction interface with the base layer.