Abstract: A horizontal type DMISFET is remarkably improved in its endurance of an over-voltage applied to a drain electrode thereof. In this MIS type semiconductor device, an N+-type source region assuming an octagonal-shaped configuration in plan view is selectively formed in a first P-type base region in a manner such that the N+-type source region is disposed adjacent to a peripheral portion of a P+-type base region, provided that the N+-type source region is not disposed on a center line through which a center of an N+-type drain region is connected with a center of the first P-type base region.

Abstract: A power field effect transistor includes a bulge portion and/or a constricted portion in at least one of the heavily doped drain contact region and the lightly doped channel forming region, and heavily doped source regions are formed in the lightly doped channel forming region at intervals, wherein the avalanche breakdown takes place at the bulge portion and/or the constricted portion due to the concentration of electric field in the presence of excess voltage applied to the heavily doped drain contact region, and the breakdown current flows through the gaps between the heavily doped source regions so that a emitter-base junction of a parasitic bipolar transistor is not strongly biased.

Abstract: A power field effect transistor includes a bulge portion and/or a constricted portion in at least one of the heavily doped drain contact region and the lightly doped channel forming region, and heavily doped source regions are formed in the lightly doped channel forming region at intervals, wherein the avalanche breakdown takes place at the bulge portion and/or the constricted portion due to the concentration of electric field in the presence of excess voltage applied to the heavily doped drain contact region, and the breakdown current flows through the gaps between the heavily doped source regions so that a emitter-base junction of a parasitic bipolar transistor is not strongly biased.

Abstract: A semiconductor device enables a semiconductor element to turn off accurately and quickly at the time of short circuit of the load to protect the semiconductor element from the short circuit of the load. The semiconductor device comprises a first switching measure for turning on/off a current flowing into the load, a current detector for detecting current flowing into the load, a second switching measure for turning on/off a connection between the current detector and the load, and a controller for controlling the first switching measure and the second switching measure. The controller turns on the first switching measure, before turning on the second switching measure at the start of driving of the load. The current detector turns off the first switching measure when detecting excess current.

Abstract: A semiconductor device including first, second, third and fourth MOSFETs constituting an H bridge circuit. Each of the first and second MOSFETs is a vertical DMOSFET and each of the third and fourth MOSFETs is a lateral DMOSFET having a surface diffusion region formed in a portion of a drain region. The surface diffusion region has a conductivity type opposite that of a source region of the lateral DMOSFET and is electrically connected to the source region. Each of the surface diffusion regions may be made of a part of a channel stop region formed under a field insulator film. Each of the third and fourth MOSFETs may be a lateral DMOSFET having no surface diffusion region. Low on-resistance and small chip size of the device are obtained.

Abstract: An antenna device used for portable electronic appliances such as electronic wristwatches furnished with a reception function. Antenna device 100 is bent conforming to the side of watch case 201 and installed on the side of watch case 201. The antenna device is composed of an antenna 110 and an antenna case 150 in which the antenna 110 is housed. The antenna case is made of or coated with a non-metallic material and formed separately from a watch case made of a metallic material. In addition, the antenna case is fixed to watch case 201 with screws 152 at positions apart from the extended line P of antenna core 111.

Abstract: A ceramic device is disclosed that has a silicon base plate, a first ceramic film formed on a first surface of the silicon base plate, a second ceramic film formed on a second surface of the silicon base plate opposite to the first surface, and an operation opening formed in the silicon base plate between the first and second surfaces. A surface portion of the first ceramic film exposed to the operation opening Is a mirror surface having 0.05 micrometers or less of center line average height Ra. A mirror surface keeping film can be formed between the first surface of the silicon base plate and the first ceramic film for keeping a mirror surface in an etching step to etch the silicon base plate, and the silicon base plate can be reduced partially in the etching step for forming an operation opening thereby exposing a corresponding portion of the mirror surface keeping film to the operation opening.

Abstract: A ceramic membrane device for a photomask is a ring-shaped base plate constituting a circumferential frame and having a flat front surface, an outer side surface and a rear surface, a front CVD coating supported on the front surface of the base plate and defining a flat surface on which a masking pattern is to be formed, and a rear CVD coating formed on the rear surface of the base plate. The front and rear CVD coatings are made of a silicon compound.

Abstract: A susceptor for use in a vertical vapor growth apparatus includes a susceptor body (12) having an upper surface, a plurality of wafer receiving portions (17) formed in the upper surface of the susceptor body (12), and plates (16) fixed in the upper surface of the susceptor body (12) near the wafer setting portions (17). The plates (16) have an upper surface such that, when wafers (5) are mounted in the wafer setting portions (17), the upper surfaces of the plates (16) and the wafers (5) are positioned substantially in the same plane. The plates (16) are made of quartz glass or fused silica.

Abstract: A mechanism for fast-forwarding/rewinding operations in which an intermittent gear driven by a motor is used for actuating a control member for advancing and releasing one or more of a head, pinch roller and idler for tape reproduction against the force of an elastic member while a lock means can lock the control member in the reproducing mode, the locked condition by the lock means being released by operation of one or both of the operation levers for fast-forwarding and rewinding operations.

Abstract: A transmission system in a cam mechanism having a cam and a driven member to be driven by the cam which comprises an electromagnetic plunger and a control member for having said driven member be driven by said cam while said electromagnetic plunger is energized and releasing said driven member from driving force of said cam when said electromagnetic plunger is deenergized.

Abstract: An operating device for switching a slide switch by moving a slide member of the slide switch in response to movement of an operating member includes an acting member which is provided on the operating member, is engageable with the slide member, and is movable against elastic force of an elastic member. The elastic force is slightly larger than the force necessary for slidable movement of the slide member and the stroke of the operating member is larger than that of the slide member.