Abstract: A high-gain monolithic antenna with high freedom of design has a signal circuit and a stripline dipole antenna which are provided on a substrate. A dielectric film and a conductor cover covering the dielectric film are provided on the upper surface of the substrate, in addition to a hole extending vertically downward to the underside of the substrate, a conductor wall being provided on the surface thereof. Furthermore, a metallic film is evaporated so as to contact both a metallic cover and a conductor wall. A first grounding conductor and a dielectric are provided on the lower surface of the substrate, and a second grounding conductor is provided on the upper surface of the substrate. A horn, which is tapered into the dielectric and the first grounding conductor thereby forming the shape of a quadrangular pyramid, is provided so as to overlap a hole etched into the substrate. Microwaves or milliwaves are radiated to/from the horn to/from the underside of the substrate.

Abstract: A semiconductor device has an active layer formed on a semiconductor substrate with different types of junctions, a source region, a drain region, a T-shaped gate electrode in which the cross-sectional area of the upper surface is larger than that of the lower surface, a first dielectric layer covering at least the exposed surface of the active layer, and the gate electrode, and a second dielectric layer enclosing the first dielectric layer. In the device, when the specific inductive capacities of the first and second dielectric layers are .epsilon.(1) and .epsilon.(2) respectively .epsilon.(1)<.epsilon.(2) and the water absorption ratio of the first dielectric layer is greater than the water absorption ratio of the second dielectric layer.

Abstract: According to this invention, there is provided a method of manufacturing a compound semiconductor which can be formed at a high yield and in which variations in characteristics of elements caused by variations in distances between a source and a gate and between a drain and the gate can be minimized. In addition, there is provided a compound semiconductor device having a structure capable of increasing a power gain and obtaining a high-speed operation. According to this invention, an active layer is formed on a compound semi-conductor substrate, and source/drain electrodes are formed on the active layer to be separated from each other. The wall insulating films are respectively formed on side walls of the electrodes, and a gate electrode is formed between the side wall insulating films to be respectively in contact therewith.

Abstract: A method of dicing a wafer of III-V compound material without causing chipping and cracks. The method includes the steps of forming a scribe line on a surface of the wafer orthogonal to a crystal plane (011) by means of a scribing method, forming a groove in the semiconductor wafer in parallel to the crystal plane (011) by means of a grinding-cutting method, and breaking the semiconductor wafer along the scribe line and the groove.

Abstract: A semiconductor device having a GaAs substrate and an ohmic electrode. An electrode pad is on part of the ohmic electrode and on part of the GaAs substrate outside the ohmic electrode. The electrode pad includes a first platinum film, a titanium film, a second platinum film, and a gold film which are sequentially deposited on one another. The first platinum film is thinner than each of the titanium film, second platinum film and gold film.

Abstract: After a silicon nitride film is deposited on a compound semiconductor substrate, another insulating film such as a silicon dioxide film is provided thereon so as to define a channel region in the semiconductor substrate. Impurity ions such as Si ions are selectively implanted into the semiconductor substrate in the presence of the silicon nitride film and the insulating film, thereby providing source and drain regions and the channel region therein. The insulating film and the silicon nitride film located above the channel region are successively removed to provide a Schottky gate electrode thereon. The silicon nitride film is selectively removed from the substrate surface to provide source and drain electrodes on their regions. Accordingly, MESFETs can be produced without exposing the substrate surface during its manufacture.