Abstract: Silicon on insulator (SOI) field effect transistors (FET) with a shared body contact, a SRAM cell and array including the SOI FETs and the method of forming the SOI FETs. The SRAM cell has a hybrid SOI/bulk structure wherein the source/drain diffusions do not penetrate to the underlying insulator layer, resulting in a FET in the surface of an SOI layer with a body or substrate contact formed at a shared contact. FETs are formed on SOI silicon islands located on a BOX layer and isolated by shallow trench isolation (STI). NFET islands in the SRAM cells include a body contact to a P-type diffusion in the NFET island. Each NFET in the SRAM cells include at least one shallow source/drain diffusion that is shallower than the island thickness. A path remains under the shallow diffusions between NFET channels and the body contact. The P-type body contact diffusion is a deep diffusion, the full thickness of the island. Bit line diffusions shared by SRAM cells on adjacent wordlines may be deep diffusions.

Abstract: A fabrication method for a non-volatile memory includes providing a first metal oxide semiconductor (MOS) transistor having a control gate and a second MOS transistor having a source, a drain, and a floating gate. The first MOS transistor and the second MOS transistor are formed on a well. The method further includes biasing the first MOS with a first biasing voltage to actuate the first MOS transistor, biasing the second MOS transistor with a second biasing voltage to enable the second MOS transistor to generate a gate current, and adjusting capacitances between the floating gate of the second MOS transistor and the drain, the source, the control gate, and the well according to voltage difference between the floating gate of the second MOS transistor and the source of the second MOS transistor.

Abstract: A method for forming a heterojunction bipolar transistor (HBT) includes forming an etch mask a top layer of the HBT to expose a portion of the emitter cap layer, and selectively etching the exposed portion of the emitter cap layer to (1) form a reentry feature and (2) to expose a portion of the emitter layer. The method further includes selectively etching the exposed portion of the emitter layer to expose a portion of the base layer, and forming a metal layer over the exposed portion of the base layer and the exposed portion of the emitter cap layer.

Abstract: With a gate electrode and side wall spacers being used as masks, ions of an n-type impurity are implanted from the normal line direction of a substrate, whereby source/drain diffused regions are formed. Then, ions of an n-type impurity are introduced by oblique implantation having a predetermined angle relative to the normal line direction of the substrate to form an n-type semiconductor region having an impurity concentration higher than source/drain extended regions. By this method, the junction depth of the semiconductor region becomes smaller than that of the source/drain diffused regions and greater than that of the source/drain extended regions.

Abstract: In the manufacturing process of a Bi-CMOS semiconductor device, which includes a CMOSFET and a bipolar transistor, the steps for forming a well region, source regions, and drain regions of the CMOSFET are also used for forming the bipolar transistor. One of the steps is used for introducing impurities of the same conductivity type in a surface of a base region of the bipolar transistor in order to form a high impurity concentration region in the surface. The high impurity concentration region is formed such that the distance between an emitter region of the bipolar transistor and the high impurity concentration region becomes 1 to 2 &mgr;m. The shift in device characteristics of the bipolar transistor is improved by the high impurity concentration region even if the impurity concentration is relatively low at the surface of the base region of the bipolar transistor.

Abstract: According to one exemplary embodiment, a method for fabricating a bipolar transistor in a BiCMOS process comprises a step of forming an emitter window stack by sequentially depositing a base oxide layer and an antireflective coating layer on a top surface of a base, where the emitter window stack does not comprise a polysilicon layer. The method further comprises etching an emitter window opening in the emitter window stack. The method further comprises depositing an emitter layer in the emitter window opening and over the antireflective coating layer and etching the emitter layer to form an emitter. The method further comprises etching a first portion of the base oxide layer not covered by the emitter using a first etchant, thereby causing the first portion of the base oxide layer to have a thickness less than a thickness of a second portion of the base oxide layer covered by the emitter.

Abstract: A high voltage semiconductor device having a high current gain hFE is formed with a collector region (20) of a first conduction type, an emitter region (40) of the first conduction type, and a base region (30) of a second conduction type opposite to the first conduction type located between the collector region and the emitter region. The free carrier density of the base region (30) where no depletion layer is formed is smaller than the space charge density of a depletion layer formed in the base region (30).

Abstract: A semiconductor device comprising: a first insulating film formed on a semiconductor substrate; a semiconductor layer at least a part of which is formed on the first insulating film; a second insulating film comprising a non-doped silicon oxide film and formed on the semiconductor layer; a third insulating film comprising a silicon oxide film containing at least phosphorus formed on the second insulating film; and a fourth insulating film comprising a non-doped silicon oxide film formed on the third insulating film.

Abstract: A process for forming at least one interface region between two regions of semiconductor material. At least one region of dielectric material comprising nitrogen is formed in the vicinity of at least a portion of a boundary between the two regions of semiconductor material, thereby controlling electrical resistance at the interface.

Abstract: The invention relates to a process of forming a compact bipolar junction transistor (BJT) that includes forming a self-aligned collector tap adjacent the emitter stack and an isolation structure. A base layer is formed from epitaxial silicon that is disposed in the substrate.

Abstract: A high frequency bipolar transistor that has a silicon germanium intrinsic base region is formed in a semiconductor fabrication process that forms the extrinsic base regions after the intrinsic base region has been formed. The extrinsic base regions are epitaxially grown single crystal silicon that is doped during the growth.

Abstract: According to one exemplary embodiment, a bipolar transistor, such as a heterojunction bipolar transistor (“HBT”), comprises a base having a top surface. The HBT further comprises a first inner spacer and a second inner spacer situated on the top surface of the base. The HBT further comprises a first outer spacer situated adjacent to the first inner spacer and a second outer spacer situated adjacent to the second inner spacer on the top surface of the base. According to this exemplary embodiment, the HBT further comprises an emitter situated between the first and second inner spacers. The HBT may further comprise an intermediate oxide layer situated on the first and second outer spacers. The HBT may further comprise an amorphous layer situated on said intermediate oxide layer. The HBT may also comprise an antireflective coating layer on the amorphous layer.

Abstract: The present invention provides a unique device structure and method that provides increased transistor performance in integrated bipolar circuit devices. The preferred embodiment of the present invention provides improved high speed performance by providing reduced base resistence. The preferred design forms the extrinsic base by diffusing dopants from a dopant source layer and into the extrinsic base region. This diffusion of dopants forms at least a portion of the extrinsic base. In particular, the portion adjacent to the intrinsic base region is formed by diffusion. This solution avoids the problems caused by traditional solutions that implanted the extrinsic base. Specifically, by forming at least a portion of the extrinsic base by diffusion, the problem of damage to base region is minimized. This reduced damage enhances dopant diffusion into the intrinsic base. Additionally, the formed extrinsic base can have improved resistence, resulting in an improved maximum frequency for the bipolar device.

Abstract: A transistor that includes a doped buried region 320 within a semiconductor body 300, 340. The doped buried region includes a portion having a first thickness 348 and a second thickness, the first thickness being less than the second thickness. In one embodiment the first thickness is about half the second thickness. The transistor also includes a collector region 342 over the buried region, a base region 396 within the collector region, and an emitter region 422 within the base region.

Abstract: A semiconductor device which has: a bipolar transistor having a collector region of a second conductivity type formed from the surface of a semiconductor substrate of a first conductivity type, a base region of a first conductivity type formed from the surface of the collector region, and an emitter region of a second conductivity type formed from the surface of the base region; a collector extraction region that is separated by an insulating layer and is formed in the collector region except the base region; a concave portion in the collector extraction region that is formed up to a depth where the collector region has a peak concentration in impurity distribution; and a collector extraction electrode that is connected with the collector region to extract ohmic-connecting to the bottom of the concave portion.

Abstract: Disclosed are structures and a method to increase the power dissipation of an output pad of an integrated circuit during electrostatic discharge (ESD) by preventing ESD current from flowing through resistive means between that output pad and an internal circuit. By splitting the active region and thereby creating a bipolar transistor which connects directly to the output pad, the resistive means is shunted when the bipolar transistor together with an already existing parasitic bipolar transistor conduct during ESD. Current flow in the resistive means is therefore eliminated and with it damaging power dissipation.

Abstract: Silicon carbide bipolar junction transistors having an overgrown base layer are provided. The bipolar junction transistors can be made with a very thin (e.g., 0.3 &mgr;m or less) base layer while still possessing adequate peripheral base resistance values. Self aligning manufacturing techniques for making the silicon carbide bipolar junction transistors are also provided. Using these techniques, the spacing between emitter and base contacts on the device can be reduced. The silicon carbide bipolar junction transistors can also be provided with edge termination structures such as guard rings to increase the blocking capabilities of the device.

Abstract: In the semiconductor integrated circuit device, a first P+ type buried layer formed as an anode region and an N+ type diffused region formed in a cathode region are spaced from each other in the direction of the depth. This makes it possible to provide a semiconductor integrated circuit device in which a large depletion layer forming region can be provided in an N type region at a PN junction formed by first and second epitaxial layers and when a reverse bias voltage is applied to a diode element and in which a withstand voltage can be maintained by a depletion layer thus formed to prevent breakdown of elements in the device attributable to a breakdown current.

Abstract: A bipolar transistor and a method for manufacturing the bipolar transistor are provided.

Abstract: A method of producing a hetero-junction bipolar transistor includes: laminating semiconductor layers that are to be a subcollector layer, a collector layer, a base layer, an emitter layer and an emitter cap layer successively on one surface of a semi-insulating substrate; and forming an electrode layer on the emitter cap layer. The method also includes adjusting the shape of the emitter cap layer to be a predetermined shape by wet etching; and removing end portions of the electrode layer so that the edges of the electrode layer are substantially aligned to the edges of the top face of the emitter cap layer. Furthermore, the method includes removing a surface oxidized layer formed on the emitter layer. Thus, defective etching of the emitter layer including an element P of group V is resolved, and a hetero-junction bipolar transistor having predetermined properties can be produced stably.

Abstract: In accordance with the invention, a process for forming a dual gate structure for CMOS devices comprises the steps of a) providing a semiconductor workpiece including n-type and p-type regions and a gate dielectric region for a dual gate structure formed over the regions, b) forming over the gate dielectric region a thin layer of semiconductor doped to one type of conductivity, c) selectively removing the doped semiconductor overlying the workpiece region of like conductivity doping and d) forming a thin layer of semiconductor doped to the opposite kind of conductivity. The doped layers are then planarized as by chemical-mechanical polishing (CMP). An additional layer of undoped semiconductor can optionally be applied to bury the doped layers, and the device can be finished by coating with metal silicide in the usual fashion. This process can be completed with only one photolithography step, simplifying device fabrication by several operations.

Abstract: A manufacturing process for a semiconductor device including a semiconductor memory region and a peripheral circuit region including bipolar transistors, in which a plurality of bipolar transistors with characteristics different from each other are effectively manufactured according to design requirements while minimizing the number of manufacturing steps. In manufacturing the semiconductor memory region and the bipolar transistors in the peripheral circuit region, a plurality of holes for forming the bipolar transistors are provided in the peripheral circuit region in correspondence to a plurality of steps for forming holes for interlayer insulating films in the semiconductor memory region, whereby the bipolar transistors with characteristics different from each other are formed in the holes of the peripheral region.

Abstract: A method of fabricating a vertical TDMOS power device using sidewall spacers and a self-align technique and a TDMOS power device of the same. The TDMOS is fabricated using only 3 masks and a source is formed using the self-align technique to embody a highly integrated trench formation. During the process, ion implantation of high concentration into the bottom of the trench makes a thick oxide film grow on the bottom and the corner of the gate, so that electrical characteristic, specifically leakage current and breakdown voltage of the device can be improved. Also, process steps can be much decreased to lower process cost, high integration is possible, and reliability of the device can be improved.

Abstract: An RF microwave power transistor has an input/output feed structure which functions as a low impedance microstrip line by providing a ground plane in close proximity to the feed structure on one surface of a semiconductor body. A second ground plane can be provided on an opposing surface of the semiconductor body with vias interconnecting the first and second ground planes. In addition to reducing feed impedance, a larger total transistor size can be provided before “odd mode oscillation” occurs.

Abstract: An electronic power device is integrated monolithically in a semiconductor substrate. The device includes a power region, itself having at least one P/N junction provided therein which comprises a first semiconductor region with a first type of conductivity extending into the substrate from the top surface of the device and being diffused into a second semiconductor region with the opposite conductivity from the first; and an edge protection structure of substantial thickness and limited planar size incorporating at least one trench filled with dielectric material.

Abstract: A method for forming a plurality of devices on a substrate is disclosed. The method includes providing an oxide layer over the substrate, forming diffused regions in the plurality of devices, and performing at least one high-energy implant in the diffused regions. The diffused regions are buried and driven. Oxide layer is then removed. The method also includes depositing an epitaxial layer over the diffused regions, such that the diffused regions are buried under the epitaxial layer, in a single row.

Abstract: The present invention is related to a bipolar transistor in which the in-situ doped epitaxial Si or SiGe base layer is used instead of using an ion-implanted Si base, in order to achieve higher cutoff frequency. The SiGe base having the narrower energy bandgap than the Si emitter allows to enhance the current gain, the cutoff frequency(fT), and the maximum oscillation frequency (fmax). The narrow bandgap SiGe base also allows to have higher base doping concentration. As a result, the intrinsic base resistance is lowered and the noise figure is thus lowered. Parasitic base resistance is also minimized by using a metallic silicide base ohmic electrode. The present invention is focused on low cost, high repeatability and reliability by simplifying the manufacturing process step.

Abstract: The invention relates to a process for providing a semiconducting device comprising the steps of depositing a semiconducting layer onto a substrate by means of heating a gas to a predetermined, dissociation temperature so that the gas dissociates into fractions, whereby these fractions subsequently condense on the substrate to build up a semiconducting layer.

Abstract: An electronic power device is integrated on a substrate of semiconductor material having a first conductivity type, on which an epitaxial layer of the same type of conductivity is grown. The power device comprises a power stage PT and a control stage CT, this latter enclosed in an isolated region having a second type of conductivity type. The power stage PT comprises a first buried area having the second type of conductivity type and a second buried area, partially overlapping the first buried area and having the first conductivity type. The isolation region and the control stage CT comprise respectively a third buried area, having the second conductivity type, and a fourth buried area, partially overlapped to the third buried area and having the first conductivity type. Said first, second, third and fourth buried areas are formed in the epitaxial layers at a depth sufficient to allow the power stage PT and the control stage CT to be entirely formed in the epitaxial layers.

Abstract: An integrated circuit and a process for making the same are provided. The circuit has a nitrogen implanted emitter window, wherein the nitrogen has been implanted into the emitter window after the emitter window etch, but prior to the emitter conductor deposition. Nitrogen implantation is expected to minimize oxide growth variation.

Abstract: A selective etching method in the fabrication of a semiconductor device is provided. The method involves the steps of: depositing an amorphous layer of semiconductor material on a monocrystalline substrate of the same semiconductor material; depositing at least one dielectric layer on the amorphous layer such as to prevent crystallization of said amorphous layer; patterning the resultant structure and thereafter etching away the dielectric layer and the amorphous semiconductor layer within a predetermined area or region; and heat-treating the resulting structure.

Abstract: The present invention relates to a method for semiconductor manufacturing of one semiconductor circuit, having a multiple of transistors NMOS1, NMOS2, NPN1, NPN2 of one type. The method comprises the steps of arranging a first region 4, 16 on a semiconductor substrate 1, and implementing two transistors of said type, having different sets of characteristics, in said first region 4, 16. The step of implementing said active devices comprises a step of creating a first 6′, 10′ and a second 6″, 10″ subregion within said first region 4, 16, and said step further comprising a step of introducing dopants having different sets of dose parameters, into a first and a second area, respectively, of said first region, said dopants being of a similar type, and a step of annealing said substrate 1 to create said first 6′, 10′ and second 6″, 10″ subregion, respectively, whereby two subregions, having different doping profiles, can be manufactured on a single integrated circuit.

Abstract: A semiconductor device for an integrated injection logic cell having a pnp bipolar transistor structure formed on a semiconductor substrate, wherein at least one layer of insulating films formed on a base region of the pnp bipolar transistor structure is comprised of a silicon nitride film. The semiconductor device of the present invention is advantageous in that the silicon nitride film constituting at least one layer of the insulating films formed on the base region of the pnp bipolar transistor prevents an occurrence of contamination on the surface of the base region, so that both the properties of the pnp bipolar transistor and the operation of the IIL cell can be stabilized. Further, by the process of the present invention, the above-mentioned excellent semiconductor device can be produced.

Abstract: A BiCMOS integrated circuit is fabricated using a minimum number of wafer processing steps and yet offers the IC circuit designer five (5) different transistor types. These types include P-channel and N-channel MOS transistors and three different bipolar transistors whose emitters are all formed by a different process and all are characterized by different current gains and different breakdown voltages. A differential silicon dioxide/silicon nitride masking technique is used in the IC fabrication process wherein both P-type buried layers (PBL) and N-type buried layers (NBL) are formed in a silicon substrate using a single mask set and further wherein P-type wells and N-type wells are formed above these buried layers in an epitaxial layer, also using a single SiO2/Si3N4 differential mask set. Two of the bipolar transistor emitters are formed by out diffusion from first and second levels of polysilicon, whereas the emitter of the third bipolar transistor is formed by ion implantation doping.

Abstract: A semiconductor integrated circuit device comprises a multiple-stage amplifier including a plurality of transistors. The multiple-stage amplifier has a first stage comprising a plurality of bipolar transistors each having a single emitter structure. The bipolar transistors are connected parallel to each other. The semiconductor integrated circuit device can easily be designed, is of a self-aligned structure, and has a single transistor size. The semiconductor integrated circuit device may be used as a low-noise, high-power-gain high-frequency amplifier.

Abstract: A method for making an improved polysilicon emitter for a bipolar transistor in a BiCMOS integrated circuit is achieved. The method uses a novel stacked undoped amorphous silicon layer and a doped polysilicon layer. The polysilicon layer is doped by ion implantation while the amorphous silicon layer remains undoped. The stacked layer is patterned to form a polysilicon emitter source over the bipolar transistor, while concurrently forming gate electrodes for the FETs. The undoped amorphous silicon layer retards the diffusion from the doped polysilicon to provide a shallower emitter junction during subsequent thermal processing. At a later step a rapid thermal anneal (RTA) is carried out in which the amorphous silicon layer provides better control of the diffused emitter depth (junction) while concurrently activating the implant dopant in the FET source/drain areas.

Abstract: A method of manufacturing a semiconductor device simultaneously forms a first vertical bipolar transistor which operates at a relatively low speed and is of a high withstand voltage and a low power requirement and a second vertical bipolar transistor which operates at a relatively high speed and is of a high power requirement. The method comprises the steps of forming openings for selectively forming single crystal base regions respectively in the vertical bipolar transistors, forming single crystal base regions via the openings, forming an insulating film on a device forming surface of a semiconductor substrate after the base regions are formed, and introducing ions of an impurity of the same conductivity type as a collection region via the insulating film. The opening in the second vertical bipolar transistor is of a size greater than the opening in the first vertical bipolar transistor.

Abstract: The present invention relates to a method for semiconductor manufacturing of one semiconductor circuit, having a multiple of transistors NMOS1, NMOS2, NPN1, NPN2 of one type. The method comprises the steps of arranging a first region 4, 16 on a semiconductor substrate 1, and implementing two transistors of said type, having different sets of characteristics, in said first region 4, 16. The step of implementing said active devices comprises a step of creating a first 6′, 10′ and a second 6″, 10″ subregion within said first region 4, 16, and said step further comprising a step of introducing dopants having different sets of dose parameters, into a first and a second area, respectively, of said first region, said dopants being of a similar type, and a step of annealing said substrate 1 to create said first 6′, 10′ and second 6″, 10″ subregion, respectively, whereby two subregions, having different doping profiles, can be manufactured on a single integrated circuit.

Abstract: A new design for a high voltage bipolar transistor is disclosed. Instead of a buried subcollector (which would be N+ in an NPN device), a buried P+ layer is used. The presence of this P+ layer results in pinch-off between itself and the bipolar base. This allows much higher breakdown voltages to be achieved. In particular, the device will not break down at the bottom of the base-collector junction which is the weak spot for conventional devices. A process for manufacturing this device is described. A particular feature of this new process is that the N type epitaxial layer that is grown over the P+ layer is only about half the thickness of its counterpart in the conventional device. The process is fully compatible with conventional BiCMOS processes and has lower cost.

Abstract: A BiCMOS integrated circuit is formed with CMOS transistors on an SOI substrate in a silicon layer having a standard thickness of 0.1 &mgr;m to 0.2 &mgr;m and with Bipolar SiGe transistors formed in an epitaxial layer nominally 0.5 &mgr;m thick. The CMOS transistors are formed first with standard processing, then covered with an insulating film. The insulating film is stripped in the bipolar areas and an epitaxial SiGe layer is deposited on the Si substrate. The bipolar transistors are formed using the SiGe epi layer for the base and having an encapsulated structure for device isolation using shallow isolation trenches and the buried oxide.

Abstract: The present invention relates to electro optical devices with a reduced filter thinning on the edge pixels and a method for reducing the thinning of filter layers on the pixels closest to the edge of an electro optical device such as a photosensitive chip, as would be used, for example, in a full-color digital copier or scanner. A semiconductor wafer includes a main surface defining a plurality of chip areas and tab regions separated by grooves, wherein the chip areas include inner photosites, outer photosites and bonding pads. A plurality of dams are deposited over the main surface in the tab regions, and a clear layer is deposited over the main surface exclusive of the bonding pads. Alternatively, a clear layer is deposited over the main surface exclusive of the bonding pads, and a plurality of tabs is then deposited in the tab regions on the main surface.

Abstract: There is provided a method of fabricating a semiconductor device, including the steps of, in sequence, (a) partially forming a buried layer in a semiconductor substrate and also forming an epitaxial layer on the buried layer, (b) forming a collector region in the epitaxial layer by selectively introducing impurities into the epitaxial layer so that the collector region reaches the buried layer, (c) forming an insulating film on the epitaxial layer, (d) forming a polysilicon film on the insulating film, (e) patterning the polysilicon film to form a base electrode, (f) forming an interlayer insulating film over the base electrode and the insulating film, (g) patterning both the interlayer insulating film and the base electrode to form a base opening at a region at which a base region is to be formed and a collector opening above the collector region, (h) side-etching portions of the insulating film located below the base electrode to form undercut hollow portions in the insulating film, (i) filling the undercut

Abstract: An integrated device in an emitter-switching configuration comprises a first bipolar transistor having a base region, an emitter region, and a collector region, a second transistor having a charge-collection terminal connected to an emitter terminal of the first transistor, and a quenching element having a terminal connected to a base terminal of the first transistor. The quenching element is formed within the base region or the emitter region of the first transistor.

Abstract: A method for forming bipolar junction transistor with high gain via formulation of high voltage device in deep submicron process is disclosed. A substrate including a first part, a second part, and a third part is primarily provided; then, a first well in the first part and a second well in the second part are formed. A plurality of field oxide regions are formed on said substrate; subsequently, two third wells are formed in said third part. The following steps are to form a fourth well in said first well in said first part and two fifth wells in said second well in said second part; and to form a first gate on said first part between said two third wells, and a second gate on said second part between said two fifth wells. Next, a first spacer against said first gate and a second spacer against said second gate are formed. Further, first ions are introduced into said first part to serve as a collector region, and into said third part to serve as a first source/drain region.

Abstract: An integrated circuit using high-performance bipolar and CMOS transistor elements on a single chip is fabricated by a simplified process requiring minimal, if any, changes in the process used for forming either type of device in accordance with a variety of possible device designs. The method according to the invention makes maximal use of self-aligned and self-masking processes to reduce the number of processing steps. The number of processing steps is further reduced by performing some steps concurrently on different device types. Further, the masking steps which are employed are reasonably misregistration tolerant, resulting in high manufacturing yield for the process. Consequently, the process according to the invention substantially eliminates the existence of trade-offs between element performance, integration density and process complexity and cost when plural technologies are integrated on the same chip.

Abstract: The invention relates to a control circuit for semiconductor devices which is formed on a substrate (1) doped by a first dopant type, the integrated circuit comprising a first epitaxial layer (2) grown on the substrate (1) and doped by the first dopant type, and an isolation well (3) doped by a second dopant type, the control circuit comprising at least a first control transistor (M1) formed in a first well (8) doped by the second dopant type and formed in the insulation well (3). Thus, the control circuit comprises at least one N-channel MOS transistor accommodated within a well in direct contact with the isolation well to eliminate a buried layer that, in prior art arrangements, involved the presence of an undesired parasitic component.

Abstract: A logic circuit is formed of an I.sup.2 L cell structure in which a difference of switching speeds at every collector in a multi-collector structure is small. In a semiconductor device in which an integrated injection logic cell including a constant current source transistor and a switch transistor is formed on a common semiconductor substrate, a first semiconductor layer (13) doped with a first conductivity type impurity and a second semiconductor layer (19) doped with a second conductivity impurity are electrically isolated from each other on a semiconductor substrate. A plurality of collector electrodes of the switch transistor and a plurality of collector regions (20) based on diffusion of impurity are formed by the second semiconductor layer (19). The first semiconductor layer (13) includes a base electrode deriving portion, and a direct contact portion which directly contacts with the semiconductor substrate between a plurality of collector regions (20).