Abstract: Formed on a grounded semiconductor substrate, via an insulation layer, is a semiconductor layer of the same conductive type as that of the substrate. Formed on the semiconductor layer are source and drain regions of the different conductive type from that of the substrate. The drain region is formed so that its portion reaches the insulation layer. A gate insulation film is formed on the semiconductor layer and a gate electrode is formed on the gate insulation film and between the source and drain regions. A conductive member is embedded in a through hole formed from a portion of the semiconductor layer to the semiconductor substrate via the insulation layer. A source electrode is formed so that the conductive member in the through hole and the source region are connected to each other by means of the source electrode. A drain electrode is connected to the drain region.

Abstract: High-frequency transistors are formed on a semiconductor substrate. Each transistor includes an emitter having a fish-bone structure, a base formed to surround the emitter, and a base lead region connected to the base. A resistor layer having the same conductivity type as that of the base lead region, and an impurity concentration and a junction depth equal to those of the base lead region is formed in the substrate. An emitter electrode is connected to the emitter and the resistor layer. A portion of the emitter electrode connected to the resistor layer has an interdigital structure, and is connected to the resistor layer at two or more contact surface portions or an interdigital surface portion. An electrode on the wiring layer side is connected to the resistor layer. A portion of the electrode connected to the resistor layer has an interdigital structure which matches with the interdigital structure of the emitter electrode.