摘要:
The present invention provides a semiconductor device for high frequency application having a high breakdown voltage and the method of manufacturing thereof. A region including a first conductivity type high impurity concentration semiconductor and a region including a first conductivity type low impurity concentration semiconductor are provided from an ohmic layer side at the side far from a semiconductor substrate of the end surface of a barrier layer opposite the semiconductor substrate and between the ohmic layer and a gate electrode. The sheet impurity concentration of the region including a first conductivity type low impurity concentration semiconductor is set to be lower than that between the bottom surface of the gate electrode at the side of the semiconductor substrate and the end surface of the channel layer opposite the semiconductor substrate. The sheet impurity concentration of the region including a first conductivity type high impurity concentration semiconductor is set to be higher than that of the region including a first conductivity type low impurity concentration semiconductor.
摘要:
A router allowing the entry hit probability of the cache to be increased is disclosed. The cache is searched using a different mask for each cache entry. A maximum or optimum cache prefix length is determined as a length of upper bits of the destination address of the received packet which are not masked by a corresponding mask. Alternatively, the cache is searched using longest prefix match (LFM). A cache entry allowing a plurality of destination addresses to be hit can be registered in the cache, resulting in increased cache hit probability.
摘要:
In a method of fabricating a semiconductor device having a MISFET of trench gate structure, a trench is formed from a major surface of a semiconductor layer of first conductivity type which serves as a drain region, in a depth direction of the semiconductor layer, a gate insulating film including a thermal oxide film and a deposited film is formed over the internal surface of the trench, and after a gate electrode has been formed in the trench, impurities are introduced into the semiconductor substrate of first conductivity type to form a semiconductor region of second conductivity type which serves as a channel forming region, and impurities are introduced into the semiconductor region of second conductivity type to form the semiconductor region of first conductivity type which serves as a source region.
摘要:
A magnetic tape apparatus for reading data from and writing data to a magnetic tape has a magnetic head for reading or writing the data, and first and second tape guides. The first tape guide has a first guide surface to guide the magnetic tape, and the first guide surface has a width that is narrower than the width of the magnetic tape. The second tape guide has a second guide surface to guide the magnetic tape, and the second guide surface has a width that is wider than the width of the magnetic tape. If the tape moves laterally against a flange on the first tape guide, the flange initially yields to the pressure of the tape. Then the flange presses against the magnetic tape to return the tape to a laterally aligned position along a tape path.
摘要:
An air cleaning system for an engine includes a main air cleaner for supplying cleaned air to an intake system of the engine and a sub-air cleaner for supplying cleaned air to an exhaust system of the engine. The main air cleaner includes a main air cleaner housing divided into a dirty air chamber and a clean air chamber by a first air cleaning element. The sub-air cleaner is disposed in the dirty air chamber, and has its own second air cleaning element, physically separated from the first air cleaning element.
摘要:
A chip feed apparatus capable of permitting a chip feed casing to be used for storage and transportation of chips in a distribution channel as well and preventing a weight of chips from being applied to a chip storage space of a hopper, resulting in positive separation and feeding of chips by the hopper. The chip feed apparatus includes a chip feed casing formed on a side surface thereof with a chip outlet, a hopper formed on a side surface thereof with a chip inlet and connected to the chip feed casing while enabling vertical movement of the hopper, a chip separating and aligning pipe inserted into a hole communicating with the chip storage space, and a chip feed path of which one end communicates with the chip separating and aligning pipe and the other end is defined at a chip pick-up position. The chip outlet of the chip feed casing is open at a lowermost end of a chip receiving space or below the lowermost end. The side surface of the chip feed casing and the side surface of the hopper are connected to each other while the chip outlet and chip inlet are kept aligned with each other.
摘要:
Source and drain electrode metals of a field effect transistor having a recessed gate electrode metal are directly connected to a high impurity concentration semiconductor layer which faces the gate electrode metal through an insulator film which defines the side wall of the recess. The source and drain electrode metals may be disposed so as to face the gate electrode metal through the side insulator film. With this arrangement, it is possible to lower the parasitic resistance between the gate electrode and another electrode of the field effect transistor, to lower the contact resistance between a semiconductor layer and the source and drain electrodes, to reduce the capacitance of the recess gate electrode and to increase the source-gate breakdown voltage, advantageously. The above-described arrangement is particularly suitable for a transistor employing a compound semiconductor, and can also be applied to semiconductor devices other than field effect transistors. Such semiconductor devices can readily be produced by forming a gate electrode metal with a self-alignment process using the lift-off method.
摘要:
Source and drain electrode metals of a field effect transistor having a recessed gate electrode metal are directly connected to a high impurity concentration semiconductor layer which faces the gate electrode metal through an insulator film which defines the side wall of the recess. The source and drain electrode metals may be disposed so as to face the gate electrode metal through the side insulator film. With this arrangement, it is possible to lower the parasitic resistance between the gate electrode and another electrode of the field effect transistor, to lower the contact resistance between a semiconductor layer and the source and drain electrodes, to reduce the capacitance of the recess gate electrode and to increase the source-gate breakdown voltage, advantageously. The above-described arrangement is particularly suitable for a transistor employing a compound semiconductor, and can also be applied to semiconductor devices other than field effect transistors. Such semiconductor devices can readily be produced by forming a gate electrode metal with a self-alignment process using the lift-off method.
摘要:
A distribution type fuel injection pump for use in a fuel injection combustion engine comprising a plunger capable of moving reciprocally along its axis and simultaneously rotating about its axis and a couple of members forming a cam mechanism having a first cam member and a second cam member. The first cam member is mounted on the plunger and the second cam member is mounted on a housing rotatably about its axis. The couple of cam members cause the plunger to reciprocally move while the plunger is rotating. The angular position of the second cam member about its axis can be controlled by a fuel injection timing control means in accordance with the engine speed. The second cam member can also turn about its axis so as to be adjusted in its angular position by a fuel injection timing adjustment when a selected operating condition of the engine, for example the engine start, is carried out.
摘要:
A fuel injection pump in which a relief channel is formed which communicates with the pump working chamber and is arranged to be blocked by a valve means, associated with a valve actuating means responsive to a pressure varying with engine r.p.m., during starting of the engine so that the fuel injection quantity is increased. Thus, improved starting characteristics of the engine can be obtained. Said relief channel may comprise a first channel communicating with the pump working chamber, and a second relief channel which has a portion thereof extending in the pump plunger to terminate in an outer periphery of the bottom end of said plunger and is so disposed as to communicate with the pump suction chamber after a predetermined delivery stroke length or prestroke has been executed. Communication between said first and second relief channels is adapted to be interrupted by said valve means at less than a predetermined engine r.p.m. As another advantagenous arrangement, the relief channel may comprise a first relief channel which consists of a port having one end communicating with the pump working chamber and the other end terminating in an outer periphery of the plunger and a communication channel having one end terminating in an inner periphery of the plunger barrel and the other end arranged for communication with a lower pressure zone, and a second relief channel allowing a restricted flow rate and communicating with the pump working chamber. The port and communication channel of said first relief channel are so disposed as to communicate with each other at the beginning of the delivery stroke of the plunger. Said first and second relief channels are arranged to be simultaneously blocked by said valve means during starting of the engine.