Abstract: A bipolar transistor and a process for manufacturing thereof is disclosed. The bipolar transistor has a self-aligned base electrode in which first and second pillars are formed within first and second trenches which act as an activated region and a collector region, respectively; a conductive impurities layer of high density formed at a bottom side of the first and second trenches and at a lower portion of an isolation wall between the first and second trenches; and a sequentially formed base and emitter layer. After connection to the base layer, a base contact electrode is formed within the first trench, and a collector contact electrode is formed by implanting second conductive impurities in the second pillar.

Abstract: A high power bipolar transistor comprises stacks of emitter, base, and collector regions and an emitter and a base connection on an obverse surface of a semiconductor substrate, and a via-hole member through the substrate between a selected one of the emitter and the base connections. A ground connection is formed on a reverse surface of the substrate. A high power bipolar transistor comprises a collector connection on a bottom surface of a semiconductor sheet having a level different from the reverse surface and a plurality of contact plugs formed through the semiconductor sheet between the collector connection and the collector regions, respectively. Preferably, the contact plugs are formed simultaneously with the via-hole member.

Abstract: Structure and fabrication details are disclosed for AlGaAs/GaAs microwave HBTs having improved thermal stability during high power operation. The use of a thermal shunt joining emitter contacts of a multi-emitter HBT is shown to improve this thermal stability and eliminate "current-crush" effects. A significant reduction in thermal resistance of the disclosed devices is also achieved by spreading the generated heat over a large substrate area using thermal lens techniques in the thermal shunt. These improvements achieve thermally stable operation of AlGaAs/GaAs HBTs up to their electronic limitations. A power density of 10 mW/.mu.m2 of emitter area is achieved with 0.6 W CW output power and 60% power-added efficiency at 10 GHz. The thermal stabilization technique is applicable to other bipolar transistors including silicon, germanium, and indium phosphide devices.

Abstract: A self-aligned heterojunction bipolar transistor is disclosed which includes a semiconductor substrate having the (100) plane as a main surface, and at least a collector region, a base region, and an emitter region having a bandgap greater than the base region. The emitter region has an under-cut mesa structure and its crystal orientation is defined in a direction other than that parallel to the ?011! direction. In neither the ?001! direction nor the ?011! direction has the transistor any outwardly slanted structure that could cause leakage current between the emitter and base and, hence, the transistor has improved electric isolation between the emitter and base although it is self-aligned.

Abstract: A method is described for fabricating a complementary, vertical bipolar sconducting structure. An N+ silicon island and a P+ silicon island separated by a first oxide layer are formed on a sapphire substrate. An NPN junction device is formed on the N+ silicon island by epitaxially growing an N-type silicon layer on the N+ silicon island. Then, a P region is created in the N-type silicon layer. An N+ region created in the P region completes the NPN junction device. Similarly, a PNP junction device is formed by epitaxially growing a P-type silicon layer on the P+ silicon island. Then, an N region is created in the P-type silicon layer. A P+ region created in the N region completes the PNP junction device.

Abstract: A bipolar transistor in which the emitter possesses a double "mesa" structure so as to achieve the maximum avoidance of the phenomena of electron/hole recombinations that have a deleterious effect on the current gain. The double mesa emitter can be made out of an alternation of materials M.sub.I /M.sub.II having different types of behavior with respect to a pair of etching methods. These materials may be GaInP and GaAs.

Abstract: The present invention is provided in order to suppress a leak current at an emitter-base junction and to implement a high-speed operation of a bipolar transistor. An n.sup.+ buried layer is formed at a surface of a p.sup.- silicon substrate. An n.sup.- epitaxial growth layer and an n.sup.+ diffused layer are formed on n.sup.+ buried layer. A p.sup.+ external base region and a p.sup.- base region are formed at a surface of n.sup.- epitaxial growth layer so as to be adjacent to each other. A first interlayer insulating layer having an opening is formed on p.sup.- base region. A groove which is located under opening and extends under first interlayer insulating layer is formed at a surface of p.sup.- base region. An n.sup.+ emitter region is formed at a bottom surface of groove within p.sup.- base region. A sidewall insulating layer is formed so as to expose n.sup.+ emitter region and to cover a sidewall of opening and to come into contact with a bottom surface of first interlayer insulating layer.

Abstract: This invention discloses a heterojunction bipolar transistor (HBT) which includes a relatively thin intrinsic collector region and a relatively thick extrinsic collector region such that collector-base capacitance is reduced and electron transit time is maintained. The fabrication of the HBT includes loading a semi-insulating substrate into an molecular beam epitaxy machine, and growing a sub-collector contact layer, a bottom collector layer and a top collector layer on the substrate. Next, the substrate is removed from the molecular beam epitaxy machine and the top collector layer is etched by a photolithographic process to produce separate intrinsic and extrinsic collector regions. Then, the substrate is again loaded into the molecular beam epitaxy machine so that the base and emitter layers can be grown. And finally, the emitter layer is etched to form an emitter mesa only over the intrinsic semiconductor region.

Abstract: A diode-connected transistor device for IC protection against electrostatic discharge (ESD) that functions as a transistor in the active region during an ESD event. The device cell includes an annular collector at the outer reaches of the cell, a circular base diffusion concentric with the collector, and an annular emitter near the outer edge of the base. The base and emitter regions are connected together by metallization external to the transistor cell. With the base contact enclosed by the annular emitter, during an ESD spike the initial reverse bias current flow is from the collector, under the emitter diffusion and out of the base contact. Eventually, as the magnitude of the ESD spike increases, the reverse biased current becomes sufficient to locally forward bias the base-emitter junction changing the primary ESD current path from collector to base, to collector to emitter, thus lowering the ESD current density in the active base-collector junction.

Abstract: A semiconductor device with a bipolar transistor formed in a layer of semiconductor material (2) provided on an insulating substrate (1), in which material a collector zone (4), a base zone (5), and an emitter zone (6) are provided below a strip of insulating material (3) situated on the layer (2), which zones are connected to contact regions (7, 8, 9, 10) lying adjacent the strip (3), three of the contact regions (8, 9, 10) lying next to one another at a same side of the strip (3), of which two (8 and 9) are connected to the base zone (5) while the third (10), which lies between the former two (8 and 9), is connected to the emitter zone (6). The three contact regions (8, 9, 10) situated next to another at the same side of the strip (3) are provided alternately in the layer of semiconductor material (2) and in a further layer of semiconductor material (19) extending up to the strip (3).

Abstract: The total base-collector capacitance of a double-heterostructure bipolar transistor device is reduced by removing semiconductor material from the extrinsic regions and replacing the removed material with a relatively-low-dielectric-constant material, The base-collector capacitance is further reduced by using a composite subcollector structure that permits the extrinsic regions to be made thicker than the intrinsic region of the device.

Abstract: In an NPN type bipolar transistor, by employing AlGaAs or InGaAs having greater band gap than silicon, for an emitter and a base, doping amount of the emitter can be made smaller than that of the base to permit improvement of reverse withstanding voltage between the base and the emitter. Therefore, B class or C class bias can be used in a microwave band to improve efficiency.

Abstract: A buried layer contact for a integrated circuit structure is provided, with particular application for a contact for a buried collector of a bipolar transistor. The buried layer contact takes the form of a sinker comprising a fully recessed trench isolated structure having dielectric lined sidewalls and filled with conductive material, e.g. doped polysilicon which contacts the buried layer. The trench isolated contact is more compact than a conventional diffused sinker structure, and thus beneficially allows for reduced transistor area. Advantageously, a reduced area sinker reduces the parasitic capacitance and power dissipation. In a practical implementation, the structure provides for an annular collector contact structure to reduce collector resistance.

Abstract: A self-aligned fully-walled monocrystalline silicon emitter-base structure for a bipolar transistor and methods for producing the structure are provided. The methods involve creating an oxide side wall surrounding a monocrystalline silicon emitter-base structure by first defining the emitter region in a base island region. Successive oxide layers are deposited on top of the emitter region and etched back to produce an oxide wall around the entire perimeter of the emitter region. In a preferred embodiment of the invention a metal silicide is also formed across the top of the base island region of the semiconductor outside of the emitter region. Since the extrinsic base region, outside of the oxide sidewalls, is entirely covered by a low resistance silicide film, the base contact area can be significantly reduced compared to prior art devices.The process results in a fully-walled emitter-base structure made of monocrystalline silicon which exhibits improved high-frequency performance.

Abstract: A semiconductor device comprises a semiconductor substrate having a main surface, a first semiconductor region of a first conductive type, formed on the main surface of the semiconductor substrate, a surrounding of the first semiconductor region is buried with a first insulation film, a second semiconductor region of a second conductive type, formed on the first insulation film and the first semiconductor region, a second insulation film, formed on the second semiconductor region, an end portion of the second insulation film is positioned above the first insulation film, and having an opening at a central portion thereof to be positioned above the first semiconductor region, and a third semiconductor region of a first conductivity type formed on a surface of the second semiconductor region exposed through the opening of the second insulation film.

Abstract: In a bipolar junction transistor of an epitaxial planar type comprising a base region, an emitter region formed in the base region, and a poly-silicon layer as an emitter poly-silicon electrode layer overlying the emitter region, the poly-silicon layer being used as an impurity diffusion source for forming the emitter region in fabrication of the transistor, the emitter poly-silicon electrode layer comprises a poly-silicon film containing an additive of one of C, O, and P overlying the emitter region and a poly-silicon layer overlying the poly-silicon film. An impurity is doped in the poly-silicon layer and is diffused into the base region through the poly-silicon film to form the emitter region in the base region in fabrication of the transistor. The poly-silicon film contains the additive and serves to prevent the poly-silicon film and the poly-silicon layer from grain growth which badly affects the impurity diffusion for forming the emitter region.

Abstract: A structural configuration and fabrication process of a bipolar junction transistor (BJT) semiconductor device having improved current gain. The fabrication process provides a P-type heavily-doped region underneath a P-type lightly-doped base region. The P-type heavily-doped region underneath the P-type lightly-doped base region prevents electron carriers from escaping from beneath the base region of the transistor, helping the collection in a collector of electron carriers emitted by an emitter of the BJT.

Abstract: A semiconductor device includes a semiconductor body (1) having a semiconductor element with connection points (2, 3) which adjoins a surface (4) of the semiconductor body (1) and is laterally insulated and surrounded by a first depression (5) in the surface (4), which depression (5) is provided with a wall (6) and a bottom (7), while the surface (4) of the semiconductor body (1) and the wall (6) and bottom (7) of the depression (5) are covered with an insulating layer (8). The connection points (2, 3) are provided in the insulating layer (8) on the surface (4) of the semiconductor body (1) and are connected to conductor tracks (10, 11) which connect the connection points (2, 3) across a wall (6) to connection surfaces (12, 13) associated with the connection points (2, 3) and situated on the bottom (7). It is found in practice that, in the case of progressive miniaturization, the manufacture of such devices leads to rejects caused by short-circuits between connection surfaces (12, 13).

Abstract: A monolithic semiconductor device includes a field effect transistor and a bipolar junction transistor with an elevated emitter structure. An elevation structure raises the BJT emitter above the plane of the base. The elevation structure increases travel distance between a heavily doped base contact region and the emitter and protects against encroachment without increasing the total surface area allocated to the BJT device. A spacer oxide separates the polysilicon base contact and the elevation structure.

Abstract: A lateral bipolar transistor capable of forming a narrow-sized diffusion region, such as a base width, is disclosed. The transistor exhibits no scattering in the direction of the depth of the width of the diffusion region. Emitter resistance is reduced by varying an impurity diffusion source at substantially a uniform concentration in a semiconductor portion and forming a diffusion region by diffusion from the impurity diffusion source. The bipolar transistor has an SOI structure. A method of making such device is also disclosed.

Abstract: A semiconductor device in which a bipolar transistor is provided, such as a BiCMOS, and a production process thereof. The device has collector region of a first conductivity type; an intrinsic base region of a second conductivity type provided on the collector region; a graft base provided on the periphery of this intrinsic base region; and an emitter region of the first conductivity type provided by self-alignment with respect to the intrinsic base. A base electrode is provided in the upper portion where the graft base is scheduled to be formed. A trench is provided by self-alignment along the end portion on the outer circumference side of this base electrode. The graft base is provided in contact with the inner circumference of this trench.

Abstract: The present invention is directed to an improved base-collector junction transistor structure capable of higher junction breakdown voltages and lower junction capacitances than bipolar transistors of the prior art. A narrow trench is used to positively affect junction breakdown voltage and junction capacitance. The trench allows the beneficial characteristics of both depletion ring and mesa structures to be utilized. Depletion zone profiles that negatively affect junction breakdown voltage are minimized by using the trench and a depletion enhancing channel.

Abstract: This is a method of fabricating a heterojunction bipolar transistor on a wafer. The method can comprise: forming a doped subcollector layer 31 on a semi-conducting substrate 30; forming a doped collector layer 32 on top of the collector layer, the collector layer doped same conductivity type as the subcollector layer; forming a doped base epilayer 34 on top of the collector layer, the base epilayer doped conductivity type opposite of the collector layer; forming a doped emitter epilayer 36, the emitter epilayer doped conductivity type opposite of the base layer to form the bipolar transistor; forming a doped emitter cap layer 37 on top of the emitter epilayer, the emitter cap layer doped same conductivity as the emitter epilayer; forming an emitter contact 38 on top of the emitter cap layer; forming a base contact on top of the base layer; forming a collector contact on top of the collector layer; and selective etching the collector layer to produce an undercut 45 beneath the base layer.

Abstract: A method of manufacturing a bipolar transistor including the steps of doping an impurity of the one conductivity type in a major surface portion of the semiconductor substrate to form a buried layer of the one conductivity type and growing an epitaxial layer on an entire surface on a major surface of the semiconductor substrate, forming a diffusion region of the opposite conductivity type in an emitter formation region on the major surface of the semiconductor substrate and forming a base connecting region in a base formation region to be in contact with the diffusion region of the opposite conductivity type, forming an insulating interlayer on the major surface of the semiconductor substrate including the diffusion region of the opposite conductivity type and the base connecting region, forming an emitter electrode layer contact hole reaching the diffusion region of the opposite conductivity type in an emitter formation region of the insulating interlayer and forming a collector region hole reaching the epit

Abstract: A bipolar transistor is provided in which the base-emitter junctions do not traverse the base but terminate inside the top surface of the base. The transistor has long emitter perimeter available for current flow and more than two emitter sides (e.g., three sides) available for current flow, which allows obtaining a low base resistance, a low emitter resistance, a low collector resistance, a low base-collector capacitance, and a small size.

Abstract: Disclosed is a fabrication of a bipolar transistor using an enhanced trench isolation so as to improve integration and performance thereof, comprising the steps of sequentially etching back portions corresponding to a trench using a trench forming mask to a predetermined depth of the buried collector to form the trench; filling an isolation insulating layer into the trench; polishing the isolation insulating layer up to a surface of the silicon oxide layer; sequentially forming a second insulating layer on the isolating insulating layer and the silicon oxide layer; removing the first polysilicon layer and the first insulating layer formed on an inactive region other than an active region defined by the trench; thermal-oxidizing the collector layer formed on the inactive region to form a thermal oxide layer; removing the second insulating layer and sequentially forming a third polysilicon, a third insulating layer and a second nitride layer; etching back layers formed on a portion of the first insulating layer

Abstract: Manufacturing a double polysilicon layer self-aligned type bipolar transistor. A polysilicon layer for emitter impurity diffusion is formed prior to the formation of a polysilicon layer for leading out a base. A first polysilicon layer containing impurities for base impurity diffusion is deposited over the entire surface of a semiconductor structure. After the first polysilicon layer is patterned into a predetermined shape, an intrinsic base layer is formed by thermally diffusing impurities from a base impurity diffusion source. Subsequently, a second polysilicon layer containing emitter impurities is formed over the base impurity diffusion source, and then patterning is performed such that the first and second polysilicon layers remain in a region narrower than the base impurity diffusion source. Thereafter, an emitter layer is formed by thermal diffusion.

Abstract: A collector-up bipolar transistor having an undercut region (522) beneath extrinsic regions of a base layer (510) and an emitter layer (508). The extrinsic emitter region is depleted of charge carriers and provides passivation for the extrinsic portion of the base layer (508). Contact to the emitter layer may be made by forming contacts on the top surface of the substrate (500) or in a recess in the backside of the substrate.

Abstract: A process for fabricating a bipolar junction transistor by forming a trench in a silicon substrate. A lightly-doped base region is formed adjacent to the sidewalls of the trench, and a heavily-doped base region is formed under the bottom of the trench. Silicon oxide layers are formed along the sidewalls and bottom of the trench with a contact window provided to expose part of the lightly-doped base region. A polysilicon layer is formed in the trench, and is heavily doped by a dopant which in turn diffuses into the lightly-doped base region through the contact window to form an emitter region. A collector region is formed in the upper surface of the lightly-doped base region.

Abstract: In a method of manufacturing a bonded semiconductor substrate, a SiGe mixed crystal layer, a silicon layer containing N-type impurities, a SiGe mixed crystal layer containing N-type impurities of high concentration, and a silicon layer containing N-type impurities of high concentration are formed in this order on a top surface of a silicon substrate by an epitaxial growth process to form a first semiconductor substrate. A silicon oxide film is formed on a surface of a silicon substrate to form a second semiconductor substrate. The first and second semiconductor substrates are bonded to each other by heat treatment, with their top surfaces contacting each other. The first semiconductor substrate is etched from the back surface thereof until the SiGe mixed crystal layer is exposed, and the SiGe mixed crystal layer is etched until the silicon layer containing N-type impurities is exposed. This method prevents the thickness of the element forming layer from varying.

Abstract: An insulated-gate bipolar transistor (IGBT) is connected in reverse-parallel with a current-regenerative diode which, for economy of manufacture, is integrated with the IGBT. Such a diode may extend laterally on an IGBT chip, with two conductivity regions forming the diode respectively connected to emitter and collector electrodes of the IGBT. Alternatively, the diode may be formed by short-circuiting a buffer layer and a collector layer. By such integration, greater device packing density can be realized.

Abstract: This invention pertains to a lateral bipolar transistor comprising an emitter, a base and a collector. The transistor exhibits improved function and overall size reduction, due to the base and emitter structure. An island forms both the base and emitter regions in the transistor structure with the base region being above the collector region, below the emitter region, and surrounded by a dielectric region. The emitter is surrounded by emitter isolation walls, which are formed approximately 0.2 microns above the plane of the dielectric region, such that any manufacturing variances will not cause the emitter isolation walls to contact the dielectric region and pinch-off the base region from the base junction region. This structure also allows the size of the base-emitter junction to be decreased without increasing the parasitic characteristics of the transistor.

Abstract: The novel bipolar transistor has at least two separated emitter contacts and no base contact, and the emitter/base p-n junction has backward diode characteristics. The transistor can function as a logic device, but can also function as an amplifying device in digital or analog circuits.

Abstract: A high frequency, high power transistor is vertically isolated by providing a thermally conductive, electrically insulating substrate, upon which the transistor components (including collector, base, and emitter) are grown, positioned directly on the heat sink and a planar top surface formed on the transistor by the base metal contact, the emitter metal contact, and the collector metal contact. Vertical isolation improves the thermal management capabilities of the transistor. Moreover, such a vertically isolated transistor is well-adapted for lateral isolation, which solves the capacitance problems inherent in conventional devices.

Abstract: A diode-connected transistor device for IC protection against electrostatic discharge (ESD) that functions as a transistor in the active region during an ESD event. The device cell includes an annular collector at the outer reaches of the cell, a circular base diffusion concentric with the collector, and an annular emitter near the outer edge of the base. The base and emitter regions are connected together by metallization external to the transistor cell. With the base contact enclosed by the annular emitter, during an ESD spike the initial reverse bias current flow is from the collector, under the emitter diffusion and out of the base contact. Eventually, as the magnitude of the ESD spike increases, the reverse biased current becomes sufficient to locally forward bias the base-emitter junction changing the primary ESD current path from collector to base, to collector to emitter, thus lowering the ESD current density in the active base-collector junction.

Abstract: A transistor with silicon on insulator (SOI) intrinsic base and a collector each formed by a low temperature epitaxial process and each orientated vertically with respect to the (SOI) substrate. The base width can be as narrow as in a conventional vertical transistor. Similarly, the collector width can be precisely controlled.

Abstract: A bipolar transistor includes insulator structures defining an active transistor zone having a base, an emitter with a side facing away from the base, and a collector with a collector terminal having a side facing away from the base. The insulator structures are disposed on the sides of the emitter and the collector terminal facing away from the base, and the insulator structures limit current flow through the active transistor zone. A process for producing the bipolar transistor includes producing a collector by selective epitaxy on a zone of a substrate surrounded by insulators. A zone for the collector is defined with a spacer technique in the following steps: photolithographically producing a first opening in a first layer exposing a surface of a second layer; including at least one insulation layer in the second layer; producing spacers at edges of the first opening; and etching a second opening in the second layer defining the zone for the collector during selective back-etching of the spacers.

Abstract: A semiconductor device with a semiconductor body (1) is provided with a first and a second bipolar transistor (T1, T2, respectively) in a cascode configuration, in which the semiconductor body (1) comprises, in that order, a collector region (10) and a base region (11) of the first transistor (T1), a region (12) which forms both an emitter region of the first transistor (T1) and a collector region of the second transistor (T2), a space charge region (13), and a base region (14) and emitter region (15) of the second transistor (T2), while the regions form pn junctions with one another which extend parallel to a main surface (2) of the semiconductor body (1). The base region (14) and the emitter region (15) of the second transistor (T2) adjoin a main surface (3) of the semiconductor body (1).

Abstract: A self-aligned process for fabricating high performance bipolar transistors for integrated circuits includes the formation of a collector contact and intrinsic collector region within an opening at the face of a semiconductor substrate. In particular, layers of oxide and polysilicon are formed on the surface of a substrate. An opening is then formed in both layers followed by the implantation of a buried collector region into the substrate at the exposed substrate face through the opening. Polysilicon contacts to the buried layer are then formed on the sidewalls of the opening. These contacts join with the polysilicon layer to form a collector contact. An oxide is then grown on the collector contact. A monocrystalline intrinsic collector is then formed from the exposed substrate face adjacent said collector contact. In this manner, the buried collector, collector contact and intrinsic collector are all formed in a self-aligned manner.

Abstract: This invention discloses a dual base heterojunction bipolar transistor for use in a number of different application. Current is introduced into one of the base contacts such that current is forced through the base region of the transistor to the other base contact. Because of the different resistances in the base, there will be a voltage potential between one side of the emitter mesa adjacent one of the base contacts and the other side of the emitter mesa adjacent the other base contact. This lateral voltage potential creates current crowding which forces the current density to travel to the perimeter of the transistor. Because the current travels mostly through the perimeter regions of the transistor, this concept can be used for testing for defects in the bulk of the base region by comparing the current gain without current crowding and with current crowding. Also, this concept can be used strictly as a gain control for a heterojunction bipolar transistor.

Abstract: A bipolar transistor with a trench. The trench extends down into a buried collector region through an emitter region, the underlying intrinsic base and collector regions at their center portion. Insulating films are formed on the sidewalls of the trench. The trench is filled with a collector-connection conductor which contacts with the buried collector region.

Abstract: A heterojunction bipolar transistor includes a collector region made of first-conduction-type InP. and a base region connected to the collector region and made of second-conduction-type In.sub.x (Ga.sub.y Al.sub.1-y).sub.1-x As where the letters "x" and "y" denote predetermined atomic fractions. The atomic fraction "x" is in the range of 0.52 to 0.53. The atomic fraction "y" is in the range of 0.35 to 0.72.

Abstract: A method is provided for forming isolated regions of oxide of an integrated circuit, and an integrated circuit formed according to the same. A pad oxide layer is formed over the integrated circuit. A nitrogen doped polysilicon layer is formed over the pad oxide layer. A thick nitride layer is then formed over the nitrogen doped polysilicon layer. An opening is formed in the nitride layer and the nitrogen doped polysilicon layer exposing a portion of the pad oxide layer. The nitrogen doped polysilicon layer is annealed encapsulating the polysilicon layer in silicon nitride. A field oxide region is then formed in the opening.

Abstract: A first region of a first conductivity type is formed in the surface of a semiconductor body, and second and third regions of a second conductivity type are formed on and under, respectively, of the first region. An electrode region formed on a first insulating film formed on the semiconductor body is connected electrically to the first region. The electrode region is defined as having an elongated first part an upper surface of which is connected to an electrode, and having a second, different part which has a substantially constant width and which width is substantially equal to the thickness of the first portion of the electrode region. A metal silicide film is formed over the upper surface of the first portion of the electrode region. The first, second and third regions can be base, emitter and collector regions, respectively, of a bipolar transistor formed in an island region of an epitaxially grown layer on a semiconductor substrate.

Abstract: A semiconductor device includes an insulating support layer on which are mounted, in succession, a conductive layer, a buried layer comprising first and second spaced portions and a semiconductor single crystal layer comprising spaced first and second portions respectively supported on the first and second spaced portions of the buried layer, the respective first and second portions having respective, first and second common sidewalls defining respective, first and second peripheries thereof and respectively comprising a transistor region and a collector electrode region. A remaining exposed surface portion of the conductive layer extends between the spaced, opposing portions of the sidewalls of the transistor and collector electrode regions.

Abstract: A semiconductor device of vertical arrangement includes an anode region formed of a first semiconductor substrate and a second semiconductor substrate joined with the first semiconductor substrate. The first semiconductor substrate forms a high-resistance layer with a predetermined impurity density, and the second semiconductor substrate forms a low-resistance layer whose impurity density is higher than that of the high-resistance layer. A PN junction is formed inside the first semiconductor substrate. The periphery of the first semiconductor substrate including the PN junction is configured in an inverted mesa structure and coated with an insulation material. With this arrangement, the semiconductor device has a high withstand voltage and enables an employment of a large diameter wafer.

Abstract: Both homojunction and heterojunction bipolar transistor structures are fabricated in unique trenched configurations so as to better utilize their surface areas by employing both the vertical and horizontal portions of their base regions with equal effectiveness. An important advantage of the unique trenched configurations is that the base region of each trenched structure is of precisely the same thickness throughout--both vertical and horizontal portions. Consequently, the transit time for charge carriers to diffuse across the base region and the base transport factor are uniform because of the uniform base thickness. Moreover, the parasitic capacitance region of each trenched structure beneath base metallization contacts is only a small portion of the entire base-collector junction region.

Abstract: A hetero junction bipolar transistor provides a contact area an area between an emitter (or collector) electrode and a wiring formed on the electrode that is larger than that of the emitter (or collector). A variation in voltage applied to an emitter (or collector)-base junctions is prevented and a stable operation of the transistor is attained. In addition, when an etching operation is carried out, an insulation film is formed on a side part of a mask. A patterning of the emitter (or collector) is then carried out and thus an emitter (or collector) having a size approximate to that of the mask is formed.

Abstract: This invention is an SOI BICMOS process which uses oxygen implanted wafers as the starting substrate. The bipolar transistor is constructed in two stacked epitaxial layers on the surface of the oxygen implanted substrate. A buried collector is formed in the first epitaxial layer that is also used for the CMOS transistors. The buried collector minimizes the collector resistance. Selective epitaxial silicon is then grown over the first epitaxial layer and is used to form the tanks for the bipolar transistors. An oxide layer is formed over the base to serve as an insulator between the emitter poly and the extrinsic base, and also as an etch stop for the emitter etch. The emitter is formed of a polysilicon layer which is deposited through an opening in the oxide layer such that the polysilicon layer contacts the epitaxial layer and overlaps the oxide layer.

Abstract: In a semiconductor device in which the surface of a semiconductor substrate which was subjected to impurity diffusion process, and includes a multilayer metal interconnection layer which is formed on top of it by alternately laminating a metal wiring layer and an interlayer insulating film, the present semiconductor device is characterized in that in a lower layer metal wiring layer there is provided a dummy wiring stripe which is arranged in parallel to two wiring stripes that are formed away from other wiring stripes at a space according to design rules. The width of the wiring stripe is augmented effectively due to the presence of the dummy stripe, and the holding quantity of the material of the coating film which constitutes a part of the interlayer insulating film is increased.