Abstract: A semiconductor device comprising a metal base providing a metal case and a through-passage connecting the inside and outside of said metal case, an electric terminal which provides a bridge selectively deposited on the insulator base allowing formation of conductive layer thereon, said insulator base and said conductive layer and is integrated with said insulator base and is insertingly engaged with the through-passage of said metal base, and a semiconductor element accommodated in said metal case, wherein a pseudo-coaxial line structure is composed of said conductive layer, insulator base, insulator bridge and metal case. Accordingly a device of the present invention is capable of stably operating even at a frequency of 10 GHz or higher.

Abstract: A semiconductor device including a metal base, a metal case and a through-passage connecting the inside and outside of the metal case, an electric terminal which provides a bridge selectively deposited on an insulator base allowing formation of conductive layer thereon. The insulator base and the conductive layer are integrated with the insulator base and the combination is insertingly engaged with the through-passage of the metal base. A semiconductor element is fixed in the metal case, in which a pseudo-coaxial line structure is formed by the conductive layer, the insulator base, the insulator bridge and the metal case. Accordingly a device of the present invention is capable of stably operating even at a frequency of 10 GHz or higher.

Abstract: A field effect semiconductor device having a compound semiconductor substrate e.g. GaAs, GaAlAs and the like, having an active region, and a gate electrode of one or more silicides of one or more refractory metals varying the composition or compositions thereof along the height of the gate electrode, resultantly varying the etching rate thereof along the height of the gate electrode. The gate electrode having a shorter length of the portion contacting the active region than of the portion remote from the active region, realized by the foregoing difference in etching rate. The gate electrode is preferably lined with a metal having a large conductivity. A pair of source and drain electrodes are produced on the active region, resultantly the field effect semiconductor device has a fast operation speed so as to be appropriate for super high frequency circuits.

Abstract: This invention relates to an ultra high speed semiconductor integrated circuit device, and in particular to a layout and connecting structure between lead terminals of a package and signal pads on a chip. The device includes a wiring board, positioned above the chip, which comprises an internal transmission line having a predetermined characteristic impedance on a dielectric insulating plate. The internal transmission line forms a strip line or coplanar transmission line including a signal line an ground conductor film. The wiring board internconnects the outer lead and bonding pads on the chip. The wiring between the internal transmission lines can cross by using a multi-layered structure. As the result of the structure of the present invention, transmission loss is reduced, and it is possible to design the wiring board having an optimum performance for ultra high speed operation of the high density integrated circuit device.

Abstract: A high power field effect semiconductor device in which the gate length per given area of a semiconductor substrate is great and a channel is formed to extend from the main surface of the semiconductor substrate toward the other main surface to make current density as uniform as possible to thereby provide a high output power and which has a construction to allow ease in the attachment of electrodes.