55results about How to "Improve trade-offs" patented technology

Depth of a termination p base region provided in a termination portion of an active region close to an edge termination structure portion is more than depth of a p-type base region provided inside the termination p base region. An n-type high-concentration region is provided from one main surface of the semiconductor substrate in the entire surface layer of one surface of a semiconductor substrate within a depth of 20 μm or less below the bottom of the termination p base region. Ratio of the impurity concentration n1 of the n-type high-concentration region (1c) to the impurity concentration n2 of an n− drift region satisfies 1.0<n1 / n2≦5.0. Reverse leakage current when operation temperature of an element is high can be reduced and trade-off between on-state voltage and switching loss can be improved. Rising peak voltage of collector voltage when a semiconductor device is off is reduced.

A parallel p-n layer (20) is provided as a drift layer between an active portion and an n+ drain region (11). The parallel p-n layer (20) is formed by an n-type region (1) and a p-type region (2) being repeatedly alternately joined. An n-type high concentration region (21) is provided on a first main surface side of the n-type region (1). The n-type high concentration region (21) has an impurity concentration higher than that of an n-type low concentration region (22) provided on a second main surface side of the n-type region (1). The n-type high concentration region (21) has an impurity concentration 1.2 times or more, 3 times or less, preferably 1.5 times or more, 2.5 times or less, greater than that of the n-type low concentration region (22). Also, the n-type high concentration region (21) has one-third or less, preferably one-eighth or more, one-fourth or less, of the thickness of a region of the n-type region (1) adjacent to the p-type region (2).

The invention belongs to the technical field of semiconductors and relates to a carrier storage type grooved-gate IGBT (insulated gate bipolar transistor). The carrier storage type IGBT is structurally provided with two split gates and a deep groove; when a device is in a closed state, a carrier storage layer of the device is exhausted by adopting assistance of a deep groove, and meanwhile, the deep grove and the split gates form a stepped structure to weaken the peak value of an electric field of an emitter, so that voltage endurance capability of the device under higher carrier storage layer concentration is obviously improved. In addition, when the device is in an open state, a layer of the carriers can be further accumulated on the surface of a deep-groove structure 8, and conduction pressure of the device is further reduced.

An apparatus schedules communications in a wireless communication system comprising a plurality of wireless stations (103-107) operable to communicate wirelessly with each other in accordance with a time division multiple access scheme. The apparatus comprises a receiver (303) for receiving resource requests from the plurality of wireless stations (103-107). A scheduler (305) schedules air interface resource to communications between the plurality wireless stations by allocating time intervals in repeating scheduling intervals. A transmitter (301) transmits scheduling messages providing indications of the scheduling to the plurality of wireless stations (103-107). An adapter (307) adapts a duration of at least one scheduling interval of the repeating scheduling intervals in response to the resource requests from the plurality of wireless stations (103-107).

The invention discloses an intake temperature control system to meet intake temperature requirement of gasoline compression ignition full conditions. An intake port of a dual-variable-valve mechanismis connected with an intake master tube that is connected with a gas compressor; an exhaust port of the dual-variable-valve mechanism is connected with an exhaust master tube; the exhaust master tubeis connected with a turbine that is connected with a post-processor; the intake master tube is provided with an intercooler; an exhaust port of the post-processor is connected with two exhaust branches; one exhaust branch is provided with a second exhaust valve, and the other exhaust branch is provided with a first exhaust valve and an exhaust heat exchanger; a shell side water outlet of the exhaust heat exchanger is connected with a shell side water inlet of the intercooler; a shell side water inlet of the exhaust heat exchanger is connected with a shell side water outlet of the intercooler;the shell side water inlet of the intercooler is connected with a water inlet of a first radiator; the shell side water outlet of the intercooler is connected with a water inlet of the first radiator;the shell side water outlet of the intercooler is connected with a water inlet of the second radiator; the shell side water inlet of the intercooler is connected with a water outlet of a cooling water passage of an engine; a water outlet of the second radiator is connected with a water inlet of the cooling water passage of the engine.