Abstract: In a fuel injection valve (1) having a nozzle body (31) with a nozzle hole (35) at its tip that is opened and closed by a nozzle needle (32) housed in the nozzle body (31), the area of contact between the nozzle needle (32) and a seat (31A) on the nozzle body (31) is provided with a coating layer (Y) to reduce the frictional resistance with the nozzle body (31). When the nozzle needle (32) seats on the seat (31A), between the time from when the tip of the nozzle needle (32) contacts the seat (31A) to when it is pressed against the seat (31A), the nozzle needle (32) slides on the surface of the nozzle body (31) with low frictional resistance. As a result, wear on the seat (31A) when the nozzle needle (32) is seated to open the valve can be kept down.

Abstract: A semiconductor switch comprises a PNPN switch including a semiconductor PNPN structure having at least three PN junctions, a first and a second transistor and a discharging means. The emitter and collector terminals of the first transistor are connected to one main terminal and a region adjacent to the one main terminal, correspondingly and respectively, of the PNPN switch. The emitter and collector of the second transistor are connected to the other main terminal of the PNPN switch and a base of the first transistor, correspondingly and respectively, and the discharging means is connected between a base of the second transistor and a region of the PNPN switch which is adjacent to the other main terminal thereof to allow discharging of charges stored in the base of the second transistor, whereby the capability of protection against dv/dt effect of the PNPN switch may be improved, and the semiconductor switch may be readily implemented in an IC structure and may respond to a rapid voltage change.

Abstract: In a monolithic semiconductor integrated circuit, when polycrystalline semiconductor is used in a portion of substrate insulatively supporting plural semiconductor single crystal regions forming circuit elements, the oxidation process of the impurity diffusion process at high temperatures and in oxygen atmosphere is started after a passivation film such as silicon oxide or silicon nitride, to prevent oxygen from diffusing or penetrating into the surface of the polycrystalline semiconductor, has been formed on the same surface. By leaving the passivation film lying on that surface during the oxidation and diffusion process warping of the substrate that may be caused due to the diffusion or penetration of oxygen into the polycrystalline semiconductor region is prevented.