Abstract: A device includes a semiconductor substrate. A step is formed at a periphery of the semiconductor substrate. A first layer, made of polysilicon doped in oxygen, is deposited on top of and in contact with a first surface of the substrate. This first layer extends at least on a wall and bottom of the step. A second layer, made of glass, is deposited on top of the first layer and the edges of the first layer. The second layer forms a boss between the step and a central area of the device.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to heterojunction bipolar transistors (HBTs) with a buried trap rich region and methods of manufacture. The structure includes: a trap rich isolation region embedded within the bulk substrate; and a heterojunction bipolar transistor above the trap rich isolation region, with its sub-collector region separated by the trap rich isolation region by a layer of the bulk substrate.

Abstract: A bipolar transistor includes a collector. The collector is formed by: a first portion of the collector which extends under an insulating trench, and a second portion of the collector which crosses through the insulating trench. The first and second portions of the collector are in physical contact.

Abstract: This disclosure relates to bipolar transistors, such as heterojunction bipolar transistors, having increased collector thickness for improved ruggedness. In some embodiments, the collector thickness can be above 1.1 microns. The collector can have at least one doping concentration grading. The collector can have a high doping concentration at a junction between the collector and the sub-collector, such as at the high end of the grading. In some embodiments, the high doping concentration can be above about 9×1016 cm?3. The collector can include a region with high doping concentration adjacent the base. The collector can include a discontinuity in the doping concentration, such as at the low end of the grading. Such bipolar transistors can be implemented, for example, in power amplifiers.

Abstract: Disclosed semiconductor structure embodiments include a bipolar junction device configured to have a high holding voltage. The device includes base, collector and emitter terminals. The high holding voltage is achieved because of a uniquely configured emitter terminal. Specifically, the device includes a base well region, which has a first-type conductivity. The emitter terminal includes, adjacent to the base well region (e.g., within and/or on the base well region), an emitter contact region, which has a second-type conductivity, and an ancillary emitter region, which abuts the emitter contact region and which has the first-type conductivity at a higher conductivity level than the base well region. Embodiments vary with regard to the shapes of the emitter contact region and ancillary emitter region. Embodiments also vary with regard to the structures used to isolate the collector terminal from the emitter terminal and with regard to the areas covered by silicide layers.

Abstract: A disclosed structure includes a fin-based bipolar junction transistor (BJT) with reduced base resistance. The BJT includes one or more semiconductor fins. Each semiconductor fin has opposing sidewalls, a first width, and a base recess, which extends across the first width through the opposing sidewalls. The BJT includes a base region positioned laterally between collector and emitter regions. The base region includes a base semiconductor layer (e.g., an intrinsic base layer), which fills the base recess and which has a second width greater than the first width such that the base semiconductor layer extends laterally beyond the opposing sidewalls. In a BJT with multiple semiconductor fins, the base recess on each semiconductor fin is filled with a discrete base semiconductor layer. The base region further includes an additional base semiconductor layer (e.g., an extrinsic base layer) covering the base semiconductor layer(s). Also disclosed is a method of forming the structure.

Abstract: A resistive splitter can include a monolithic substrate and a patterned resistive layer formed over the monolithic substrate. The resistive splitter can include a first terminal, a second terminal, and a third terminal each connected with the patterned resistive layer. The resistive splitter can include at least one frequency compensating conductive layer formed over a portion of the patterned resistive layer. In some embodiments, the resistive splitter can exhibit a first insertion loss response between the first terminal and the second terminal that is greater than about ?10 dB for frequencies ranging from about 0 GHz up to about 30 GHz.

Abstract: Embodiments of the disclosure provide a lateral bipolar transistor with a base layer of varying horizontal thickness, and related methods to form the same. A lateral bipolar transistor may include an emitter/collector (E/C) layer on a semiconductor layer. A first base layer is on the semiconductor layer and horizontally adjacent the E/C layer. The first base layer has a lower portion having a first horizontal width from the E/C layer. The first base layer also has an upper portion on the lower portion, with a second horizontal width from the E/C layer greater than the first horizontal width. A second base layer is on the first base layer and adjacent a spacer. The upper portion of the first base layer separates a lower surface of the second base layer from the E/C layer.

Abstract: A device includes a semiconductor substrate. A step is formed at a periphery of the semiconductor substrate. A first layer, made of polysilicon doped in oxygen, is deposited on top of and in contact with a first surface of the substrate. This first layer extends at least on a wall and bottom of the step. A second layer, made of glass, is deposited on top of the first layer and the edges of the first layer. The second layer forms a boss between the step and a central area of the device.

Abstract: A semiconductor device and a semiconductor package including the same are provided. The semiconductor device includes a semiconductor element; a protective layer disposed adjacent to the surface of the semiconductor element, the protective layer defining an opening to expose the semiconductor element; a first bump disposed on the semiconductor element; and a second bump disposed onto the surface of the protective layer. The first bump has a larger cross-section surface area than the second bump.

Abstract: A bipolar junction transistor is provided with an emitter structure that is positioned above the upper surface of the base region. The thickness of the emitter and the interfacial oxide thickness between the emitter and the base is configured to optimize a gain for a given type of transistor. A method of fabricating PNP and NPN transistors on the same substrate using a complementary bipolar fabrication process is provided. The method enables the emitter structure for the NPN transistor to be defined separately to that of the PNP transistor. This is achieved by epitaxially growing the emitter layer for the PNP transistor and growing the emitter layer for the NPN transistor in a thermal furnace.

Abstract: An integrated circuit includes a bipolar transistor, e.g. a back-ballasted NPN, that can conduct laterally and vertically. At a low voltage breakdown and low current conduction occur laterally near a substrate surface, while at a higher voltage vertical conduction occurs in a more highly-doped channel below the surface. A relatively high-resistance region at the surface has a low doping level to guide the conduction deeper into the collector.

Abstract: A transistor device includes transistor cells each having source and drift regions of a first doping type and a body region of a second doping type in a first region of a semiconductor body, and a gate electrode dielectrically insulated from the body region. A gate conductor arranged on top of a second region of the semiconductor body is electrically connected to each gate electrode. A source conductor arranged on top of the first region is connected to each source and body region. A discharging region of the second doping type is arranged in the second region and located at least partially below the gate conductor, and includes at least one lower dose section in which a doping dose is lower than a minimum doping dose in other sections of the discharging region. The at least one lower dose section is associated with a corner of the gate conductor.

Abstract: A two-terminal biristor in which a polysilicon emitter layer is inserted and a method of manufacturing the same are provided. The method of manufacturing the two-terminal biristor according to an embodiment of the present disclosure includes forming a first semiconductor layer of a first type on a substrate, forming a second semiconductor layer of a second type on the first semiconductor layer, forming a third semiconductor layer of the first type on the second semiconductor layer, and forming a polysilicon layer of the first type on the third semiconductor layer.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to a device with a marker layer and methods of manufacture. The device includes: a collector region; an intrinsic base region above the collector region; an emitter region comprising emitter material and a marker layer vertically between the intrinsic base region and the emitter material; and an extrinsic base region in electrical contact with the intrinsic base region.

Abstract: A memory device includes a first electrode line layer including a plurality of first electrode lines extending on a substrate in a first direction and being spaced apart from each other, a second electrode line layer including a plurality of second electrode lines extending on the first electrode line layer in a second direction that is different from the first direction and being spaced apart from each other, and a memory cell layer including a plurality of first memory cells located at a plurality of intersections between the plurality of first electrode lines and the plurality of second electrode lines, each first memory cell including a selection device layer, an intermediate electrode and a variable resistance layer that are sequentially stacked. A side surface of the variable resistance layer is perpendicular to a top surface of the substrate or inclined to be gradually wider toward an upper portion of the variable resistance layer.

Abstract: A memory device includes a first electrode line layer including a plurality of first electrode lines extending on a substrate in a first direction and being spaced apart from each other, a second electrode line layer including a plurality of second electrode lines extending on the first electrode line layer in a second direction that is different from the first direction and being spaced apart from each other, and a memory cell layer including a plurality of first memory cells located at a plurality of intersections between the plurality of first electrode lines and the plurality of second electrode lines, each first memory cell including a selection device layer, an intermediate electrode and a variable resistance layer that are sequentially stacked. A side surface of the variable resistance layer is perpendicular to a top surface of the substrate or inclined to be gradually wider toward an upper portion of the variable resistance layer.

Abstract: Methods, systems and apparatuses are disclosed for incorporating an illumination assembly comprising a plurality of micro-light sources into an exterior surface of a vehicle for the purpose of producing predetermined fixed or sequenced visual images.

Abstract: A FinFET device structure is provided. The FinFET device structure includes a fin structure formed over a substrate, and the substrate includes a first region and a second region. A gate structure is formed over a fin structure and a first S/D structure has a first volume. A second S/D structure has a second volume, and the second volume is lower than the first volume. A first contact structure is formed over the first S/D structure and a first conductive via is formed over the first contact structure. A power line is formed over the first conductive via, and the power line is electrically connected to the first S/D structure by the first conductive via and the first contact structure.

Abstract: A bipolar junction transistor (BJT) containing sensor that includes a vertically oriented stack of an emitter overlying a supporting substrate, a base region present directly atop the emitter and a collector atop the base region. A first extrinsic base region is in contact with a first sidewall of a vertically oriented base region. The first extrinsic base region is electrically contacted to provide the bias current of the bipolar junction transistor during sensor operation. A second extrinsic base region is in contact with a second sidewall of the base region. The second extrinsic base region includes a sensing element. A sample trench is present adjacent to the BJT having a trench sidewall provided by the sensing element.

Abstract: A semiconductor device having a first surface formed at a first height and a second surface formed at a second height on a semiconductor substrate includes: a base region formed in the semiconductor substrate; a trench formed from the first surface and the second surface into the semiconductor substrate; a gate insulating film covering an inner side of the trench; a gate electrode embedded to a third height; an insulating film formed on the gate electrode; a first region which has the first surface and in which a base contact region is formed; and a second region which has the second surface and in which a source region is formed, the first region and the second region being alternately arranged in the trench extension direction to prevent a reduction in channel formation density.

Abstract: A semiconductor device (A1) includes a semiconductor layer having a first face with a trench (3) formed thereon and a second face opposite to the first face, a gate electrode (41), and a gate insulating layer (5). The semiconductor layer includes a first n-type semiconductor layer (11), a second n-type semiconductor layer (12), a p-type semiconductor layer (13), and an n-type semiconductor region (14). The trench (3) is formed so as to penetrate through the p-type semiconductor layer (13) and to reach the second n-type semiconductor layer (12). The p-type semiconductor layer (13) includes an extended portion extending to a position closer to the second face of the semiconductor layer than the trench (3) is. Such structure allows suppressing dielectric breakdown in the gate insulating layer (5).

Abstract: An approach for heat dissipation in integrated circuit devices is provided. A method includes forming an isolation layer on an electrically conductive feature of an integrated circuit device. The method also includes forming an electrically conductive layer on the isolation layer. The method additionally includes forming a plurality of nanowire structures on a surface of the electrically conductive layer.

Abstract: A battery electrode in accordance with various embodiments may include: a substrate including a surface configured to face an ion-carrying electrolyte; and a first diffusivity changing region at a first portion of the surface, wherein the first diffusivity changing region is configured to change diffusion of ions carried by the electrolyte into the substrate, and wherein a second portion of the surface is free from the first diffusivity changing region.

Abstract: A fin-type bipolar semiconductor device includes a base region having a first portion in a semiconductor substrate and a first semiconductor fin on the adjacent first portion, a collector region having a second portion in the semiconductor substrate and a second semiconductor fin on the adjacent second portion, and an emitter region having a third region in the semiconductor substrate and a third semiconductor fin on the adjacent third portion. The second portion is adjacent the first portion, and the third portion is adjacent the first portion and forms an emitter junction in the semiconductor substrate. The second portion is not adjacent to the third portion. The first, second, and third semiconductor fins are physically separated from each other. The fin-type bipolar device exhibits low leakage current, good linearity and uniformity of electrical characteristics to facilitate device matching.

Abstract: Embodiments of semiconductor devices, integrated circuit devices and methods are disclosed. In some embodiments, a semiconductor device may include a first fin and a second fin disposed on a substrate. The first fin may have a portion including a first material disposed between a second material and the substrate, the second material disposed between a third material and the first material, and the third material disposed between a fourth material and the second material. The first and third materials may be formed from a first type of extrinsic semiconductor, and the second and fourth materials may be formed from a second, different type of extrinsic semiconductor. The second fin may be laterally separated from the first fin and materially contiguous with at least one of the first, second, third or fourth materials. Other embodiments may be disclosed and/or claimed.

Abstract: A structure, including a bipolar junction transistor and method of fabrication thereof, is provided herein. The bipolar junction transistor includes: a substrate including a substrate region having a first conductivity type; an emitter region over a first portion of the substrate region, the emitter region having a second conductivity type; a collector region over a second portion of the substrate region, the collector region having the second conductivity type; and, a base region overlie structure disposed over, in part, the substrate region. The base region overlie structure separates the emitter region from the collector region and aligns to a base region of the bipolar junction transistor within the substrate region, between the first portion and the second portion of the substrate region.

Abstract: A method of forming a superconductor tape, includes depositing a superconductor layer on a substrate, forming a metal layer comprising a first metal on a surface of the superconductor layer, and implanting an alloy species into the metal layer where the first metal forms a metal alloy after the implanting the alloy species.

Abstract: A semiconductor component includes semiconductor fins formed between a base plane and a main surface of a semiconductor body. Each semiconductor fin includes a source region formed between the main surface and a channel/body region, and a drift zone formed between the channel/body region and the base plane. The semiconductor component further includes gate electrode structures on two mutually opposite sides of each channel/body region, and a field electrode structure between mutually adjacent ones of the semiconductor fins. Each field electrode structure is separated from the drift zone by a field dielectric and extends from the main surface as far as the base plane. The gate electrode structures assigned to the mutually adjacent semiconductor fins enclose an upper portion of the corresponding field electrode structure from two sides.

Abstract: Device structures and fabrication methods for a bipolar junction transistor. A layer is formed on a top surface of a substrate. A trench is formed in the layer and has a plurality of sidewalls with a width between an opposite pair of the sidewalls that varies with increasing distance from the top surface of the substrate. A collector pedestal of the bipolar junction transistor is formed in the trench.

Abstract: A bipolar transistor includes a substrate having a semiconductor surface, a first trench enclosure and a second trench enclosure outside the first trench enclosure both at least lined with a dielectric extending downward from the semiconductor surface to a trench depth, where the first trench enclosure defines an inner enclosed area. A base and an emitter formed in the base are within the inner enclosed area. A buried layer is below the trench depth including under the base. A sinker diffusion includes a first portion between the first and second trench enclosures extending from a topside of the semiconductor surface to the buried layer and a second portion within the inner enclosed area, wherein the second portion does not extend to the topside of the semiconductor surface.

Abstract: Novel etch techniques are provided for shaping silicon features below the photolithographic resolution limits. FinFET devices are defined by recessing oxide and exposing a silicon protrusion to an isotropic etch, at least in the channel region. In one implementation, the protrusion is contoured by a dry isotropic etch having excellent selectivity, using a downstream microwave plasma etch.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. A first isolation region is formed in a substrate to define a lateral boundary for an active device region and an intrinsic base layer is formed on the substrate. The intrinsic base layer has a section overlying the active device region. After the intrinsic base layer is formed, the first isolation region is partially removed adjacent to the active device region to define a trench that is coextensive with the substrate in the active device region and that is coextensive with the first isolation region. The trench is at least partially filled with a dielectric material to define a second isolation region.

Abstract: Methods are provided for forming a device that includes merged vertical and lateral transistors with collector regions of a first conductivity type between upper and lower base regions of opposite conductivity type that are Ohmically coupled via intermediate regions of the same conductivity type and to the base contact. The emitter is provided in the upper base region and the collector contact is provided in outlying sinker regions extending to the thin collector regions and an underlying buried layer. As the collector voltage increases part of the thin collector regions become depleted of carriers from the top by the upper and from the bottom by the lower base regions. This clamps the collector regions' voltage well below the breakdown voltage of the PN junction formed between the buried layer and the lower base region. The gain and Early Voltage are increased and decoupled and a higher breakdown voltage is obtained.

Abstract: Integrated circuits and methods for fabricating integrated circuits are provided. In an exemplary embodiment, a method for fabricating integrated circuits includes forming a metal contact structure that is electrically connected to a device. A capping layer is selectively formed on the metal contact structure, and an interlayer dielectric material is deposited over the capping layer. A metal hard mask is deposited and patterned over the interlayer dielectric material to define an exposed region of the interlayer dielectric material. The method etches the exposed region of the interlayer dielectric material to expose at least a portion of the capping layer. The method includes removing the metal hard mask with an etchant while the capping layer physically separates the metal contact structure from the etchant. A metal is deposited to form a conductive via electrically connected to the metal contact structure through the capping layer.

Abstract: Memory cells having memory elements self-aligned with the emitters of bipolar junction transistor access devices are described herein, as well as methods for manufacturing such devices. A memory device as described herein comprises a plurality of memory cells. Memory cells in the plurality of memory cells include a bipolar junction transistor comprising an emitter comprising a pillar of doped polysilicon. The memory cells include an insulating element over the emitter and having an opening extending through the insulating layer, the opening centered over the emitter. The memory cells also include a memory element within the opening and electrically coupled to the emitter.

Abstract: A semiconductor device, comprising a substrate layer made of a semiconductor material of a first conductivity type and having a first insulation region, and a vertical bipolar transistor having a first vertical portion of a collector made of monocrystalline semiconductor material of a second conductivity type and disposed in an opening of the first insulation region, a second insulation region lying partly on the first vertical portion of the collector and partly on the first insulation region and having an opening in the region of the collector, in which opening a second vertical portion of the collector made of monocrystalline material is disposed, said portion including an inner region of the second conductivity type, a base made of monocrystalline semiconductor material of the first conductivity type, a base connection region surrounding the base in the lateral direction, a T-shaped emitter made of semiconductor material of the second conductivity type and overlapping the base connection region, wherein t

Abstract: Lateral PNP bipolar junction transistors and design structures for a lateral PNP bipolar junction transistor. An emitter and a collector of the lateral PNP bipolar junction transistor are comprised of p-type semiconductor material that is formed by a selective epitaxial growth process. The source and drain each directly contact a top surface of a device region used to form the emitter and collector. A base contact may be formed on the top surface and overlies an n-type base defined within the device region. The emitter is laterally separated from the collector by the base contact. Another base contact may be formed in the device region that is separated from the other base contact by the base.

Abstract: A method for fabricating a photovoltaic device includes forming a patterned layer on a doped emitter portion of the photovoltaic device, the patterned layer including openings that expose areas of the doped emitter portion and growing an epitaxial layer over the patterned layer such that a crystalline phase grows in contact with the doped emitter portion and a non-crystalline phase grows in contact with the patterned layer. The non-crystalline phase is removed from the patterned layer. Conductive contacts are formed on the epitaxial layer in the openings to form a contact area for the photovoltaic device.

Abstract: Provided is a method for manufacturing a stretchable thin film transistor. The method for manufacturing a stretchable thin film transistor includes forming a mold substrate, forming a stretchable insulator on the mold substrate, forming a flat substrate on the stretchable insulator, removing the mold substrate, forming discontinuous and corrugated wires on the stretchable insulator, forming a thin film transistor connected between the wires, and removing the flat substrate.

Abstract: A heterojunction bipolar transistor (HBT) is provided with an improved on-state breakdown voltage VCE. The improvement of the on-state breakdown voltage for the HBT improves the output power characteristics of the HBT and the ability of the HBT to withstand large impedance mismatch (large VSWR). The improvement in the on-state breakdown voltage is related to the suppression of high electric fields adjacent a junction of a collector layer and a sub-collector layer forming a collector region of the HBT.

Abstract: A structure is provided in which the back gate regions are physically separated from one another as opposed to using reversed biased pn junction diodes. In the present disclosure, the back gate regions can be formed first through a buried dielectric material of an extremely thin semiconductor-on-insulator (ETSOI) substrate. After dopant activation, standard device fabrication processes can be performed. A semiconductor base layer portion of the ETSOI substrate can then be removed from the original ETSOI to expose a surface of the back gates.

Abstract: A hybrid plasma semiconductor device has a thin and flexible semiconductor base layer. An emitter region is diffused into the base layer forming a pn-junction. An insulator layer is upon one side the base layer and emitter region. Base and emitter electrodes are isolated from each other by the insulator layer and electrically contact the base layer and emitter region through the insulator layer. A thin and flexible collector layer is upon an opposite side of the base layer. A microcavity is formed in the collector layer and is aligned with the emitter region. Collector electrodes are arranged to sustain a microplasma within the microcavity with application of voltage to the collector electrodes. A depth of the emitter region and a thickness of the base layer are set to define a predetermined thin portion of the base layer as a base region between the emitter region and the microcavity. Microplasma generated in the microcavity serves as a collector.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. A first isolation region is formed in a substrate to define a lateral boundary for an active device region and an intrinsic base layer is formed on the substrate. The intrinsic base layer has a section overlying the active device region. After the intrinsic base layer is formed, the first isolation region is partially removed adjacent to the active device region to define a trench that is coextensive with the substrate in the active device region and that is coextensive with the first isolation region. The trench is at least partially filled with a dielectric material to define a second isolation region.

Abstract: Preferred embodiment flexible and on wafer hybrid plasma semiconductor devices have at least one active solid state semiconductor region; and a plasma generated in proximity to the active solid state semiconductor region(s). A preferred device is a hybrid plasma semiconductor device having base, emitting and microcavity collector regions formed on a single side of a device layer. Visible or ultraviolet light is emitted during operation by plasma collectors in the array. In preferred embodiments, individual PBJTs in the array serve as sub-pixels of a full-color display.

Abstract: Methods and apparatus for bipolar junction transistors (BJTs) are disclosed. A BJT comprises a collector made of p-type semiconductor material, a base made of n-type well on the collector; and an emitter comprising a p+ region on the base and a SiGe layer on the p+ region. The BJT can be formed by providing a semiconductor substrate comprising a collector, a base on the collector, forming a sacrificial layer on the base, patterning a first photoresist on the sacrificial layer to expose an opening surrounded by a STI within the base; implanting a p-type material through the sacrificial layer into an area of the base, forming a p+ region from the p-type implant; forming a SiGe layer on the etched p+ region to form an emitter. The process can be shared with manufacturing a polysilicon transistor up through the step of patterning a first photoresist on the sacrificial layer.

Abstract: A semiconductor device includes an active section for a main current flow and a breakdown withstanding section for breakdown voltage. An external peripheral portion surrounds the active section on one major surface of an n-type semiconductor substrate. The breakdown withstanding section has a ring-shaped semiconductor protrusion, with a rectangular planar pattern including a curved section in each of four corners thereof, as a guard ring. The ring-shaped semiconductor protrusion has a p-type region therein, is sandwiched between a plurality of concavities deeper than the p-type region, and has an electrically conductive film across an insulator film on the surface thereof. Because of this, it is possible to manufacture at low cost a breakdown withstanding structure with which a high breakdown voltage is obtained in a narrow width, wherein there is little drop in breakdown voltage, even when there are variations in a patterning process of a field oxide film.

Abstract: High voltage bipolar transistors built with a BiCMOS process sequence exhibit reduced gain at high current densities due to the Kirk effect. Threshold current density for the onset of the Kirk effect is reduced by the lower doping density required for high voltage operation. The widened base region at high collector current densities due to the Kirk effect extends laterally into a region with a high density of recombination sites, resulting in an increase in base current and drop in the gain. The instant invention provides a bipolar transistor in an IC with an extended unsilicided base extrinsic region in a configuration that does not significantly increase a base-emitter capacitance. Lateral extension of the base extrinsic region may be accomplished using a silicide block layer, or an extended region of the emitter-base dielectric layer. A method of fabricating an IC with the inventive bipolar transistor is also disclosed.

Abstract: A semiconductor device includes a plurality of parallel-trenches that are parallel to each other, a plurality of intersect-trenches that are parallel to each other, a plurality of active regions that are confined by the parallel-trenches and the intersect-trenches, a plurality of lower conductive lines that cross the active regions, a plurality of upper conductive lines that are parallel to each other, that cross the lower conductive lines, and that cross over the active regions, and data storage elements connected to the active regions. Each of the parallel-trenches and the intersect-trenches is a straight line. The parallel-trenches cross the upper conductive lines and form a first acute angle with the upper conductive lines. The intersect-trenches cross the parallel-trenches and form a second acute angle with the parallel-trenches.

Abstract: Methods for fabricating bipolar junction transistors, bipolar junction transistors made by the methods, and design structures for a bipolar junction transistor. The bipolar junction transistor includes a dielectric layer on an intrinsic base and an extrinsic base at least partially separated from the intrinsic base by the dielectric layer. An emitter opening extends through the extrinsic base and the dielectric layer. The dielectric layer is recessed laterally relative to the emitter opening to define a cavity between the intrinsic base and the extrinsic base. The cavity is filled with a semiconductor layer that physically links the extrinsic base and the intrinsic base together.