Abstract: A semiconductor device includes: a semiconductor substrate of a compound semiconductor material; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially disposed on the semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being compound semiconductor materials; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The carrier density in the channel layer varies with distance from a top surface of the channel layer and is inversely proportional to the third power of depth into the channel layer from the top surface of the channel layer. The buffer layer has a lower electron affinity than the channel layer and is a different compound semiconductor material from the channel layer.

Abstract: A semiconductor device includes: a semiconductor substrate of a compound semiconductor material; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially disposed on the semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being compound semiconductor materials; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The carrier density in the channel layer varies with distance from a top surface of the channel layer and is inversely proportional to the third power of depth into the channel layer from the top surface of the channel layer. The buffer layer has a lower electron affinity than the channel layer and is a different compound semiconductor material from the channel layer.

Abstract: A semiconductor device includes: a compound semiconductor substrate; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially disposed on the compound semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being compound semiconductor materials; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The dopant impurity concentration in the channel layer is inversely proportional to the third power of depth into the channel layer from a top surface of the channel layer. The gate electrode has a gate length in a range from 0.2 ?m to 0.6 ?m.

Abstract: A semiconductor device includes: a compound semiconductor substrate; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially disposed on the compound semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being compound semiconductor materials; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The dopant impurity concentration in the channel layer is inversely proportional to the third power of depth into the channel layer from a top surface of the channel layer. The gate electrode has a gate length in a range from 0.2 ?m to 0.6 ?m.

Abstract: A semiconductor device includes: a compound semiconductor substrate; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially formed on the compound semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being a compound semiconductor; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The dopant impurity concentration profile in the channel layer is inversely proportional to the third power of depth into the channel layer from a top surface of the channel layer. The channel layer has fixed sheet dopant impurity concentration, and the top surface of the channel layer has a dopant concentration in a range from 5.0×1017 cm?3 to 2.0×1018 cm?3.

Abstract: In a semiconductor device, a SiN first protective insulating film is formed on a semiconductor layer. A T-shaped gate electrode is formed on the semiconductor layer. A SiN second protective insulating film spreads in an umbrella shape from above the T-shaped gate electrode. A hollow region is formed between the two SiN films. The SiN films are coated with a SiN third protective insulating film with the hollow region remaining.

Abstract: In a semiconductor device, a SiN first protective insulating film is formed on a semiconductor layer. A T-shaped gate electrode is formed on the semiconductor layer. A SiN second protective insulating film spreads in an umbrella shape from above the T-shaped gate electrode. A hollow region is formed between the two SiN films. The SiN films are coated with a SiN third protective insulating film with the hollow region remaining.

Abstract: A semiconductor device includes: a compound semiconductor substrate; a buffer layer, a channel layer, and a Schottky junction forming layer sequentially formed on the compound semiconductor substrate, the buffer layer, the channel layer, and the Schottky junction forming layer each being a compound semiconductor; a source electrode and a drain electrode located on the Schottky junction forming layer; and a gate electrode disposed between the source and drain electrodes and forming a Schottky junction with the Schottky junction forming layer. The carrier density in the channel layer is inversely proportional to the third power of depth into the channel layer from a top surface of the channel layer, the channel layer has a uniform sheet carrier density, and the top surface of the channel layer has a dopant concentration in a range from 5.0×1017 cm?3 to 2.0×1018 cm?3.

Abstract: To remove the disparate substrate from nitride semiconductor layer grown over the disparate substrate, that is made of a material different from nitride semiconductor, by irradiating the disparate substrate with laser beam having a wavelength shorter than the band gap wavelength of the nitride semiconductor layer, while supplying an acidic or alkaline etching solution to the interface between the disparate substrate and the nitride semiconductor layer.

Abstract: A semiconductor device packaged in a non-hermetic package includes a semiconductor substrate; a wiring metal film on the semiconductor substrate; a plating power supply film on the wiring metal film; an Au plated portion on the plating power supply film; a metal film covering the Au plated portion; and an insulating protective film covering the metal film. The metal film is a material having corrosion resistance properties such that a potential-pH diagram of the metal material predominantly includes a corrosion-free region and a passive region and either does not include a corrosion region or includes a very small corrosion region, the potential-pH diagram showing the effects of electrical potential and pH on corrosion of the metal material.

Abstract: To remove the disparate substrate from nitride semiconductor layer grown over the disparate substrate, that is made of a material different from nitride semiconductor, by irradiating the disparate substrate with laser beam having a wavelength shorter than the band gap wavelength of the nitride semiconductor layer, while supplying an acidic or alkaline etching solution to the interface between the disparate substrate and the nitride semiconductor layer.

Abstract: Disclosed is a run flat tire for motorcycles having a high handling stability, cornering stability and durability even when the tire is punctured during running and the pneumatic pressure inside of the tire becomes equal to atmospheric pressure. The run flat tire has a pair of sidewall-reinforcing layers each comprising (1) an elastic filler extending from an end location adjacent a bead core in a bead portion to the other end location in a tread portion through a sidewall portion of the tire and (2) at least one reinforcing ply which extends along one side surface of the elastic filler toward the tread portion, is turned up around the end of the elastic filler in the tread portion and which then further extends along the other side surface of the elastic filler toward the bead portion.