Abstract: Embodiments of a three-dimensional (3D) memory device and fabrication methods are disclosed. In some embodiments, the 3D memory device includes a peripheral circuitry formed on a first substrate. The peripheral circuitry includes a plurality of peripheral devices on a first side of the first substrate, a first interconnect layer, and a deep-trench-isolation on a second side of the first substrate, wherein the first and second sides are opposite sides of the first substrate and the deep-trench-isolation is configured to provide electrical isolation between at least two neighboring peripheral devices. The 3D memory device also includes a memory array formed on a second substrate. The memory array includes at least one memory cell and a second interconnect layer, wherein the second interconnect layer of the memory array is bonded with the first interconnect layer of the peripheral circuitry, and the peripheral devices are electrically connected with the memory cells.

Abstract: A transistor with an emitter, base, and collector. The base includes a monocrystalline base layer. A sacrificial material is formed on the monocrystalline base layer. The sacrificial material is removed to expose a portion of the monocrystalline base layer. A base silicide includes a portion formed on the portion of the base monocrystalline base layer that was exposed by the removal of the sacrificial material.

Abstract: On a single-crystal semiconductor substrate with an upper surface including a first direction in which an inverted mesa step extends and a second direction in which a forward mesa step extends in response to anisotropic etching in which an etching rate depends on crystal plane orientation, a bipolar transistor including a collector layer, a base layer, and an emitter layer that are epitaxially grown, and a base wire connected to the base layer are arranged. A step is provided at an edge of the base layer, and the base wire is extended from inside to outside of the base layer in a direction intersecting the first direction in a plan view. An intersection of the edge of the base layer and the base wire has a disconnection prevention structure that makes it difficult for step-caused disconnection of the base wire to occur.

Abstract: A semiconductor device and a method of making a semiconductor device. The device includes an emitter. The device also includes a collector. The device further includes a base stack. The base is located between the emitter and the collector. The base stack includes an intrinsic base region. The device further includes a base electrode. The base electrode comprises a silicide. The silicide of the base electrode may be in direct contact with the base stack. The device may be a heterojunction bipolar transistor.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to heterojunction bipolar transistors and methods of manufacture. The structure includes: a sub-collector region in a substrate; a collector region above the sub-collector region, the collector region composed of semiconductor material; an intrinsic base region composed of intrinsic base material surrounded by the semiconductor material above the collector region; and an emitter region above the intrinsic base region.

Abstract: A power amplifier including a first transistor for amplifying and outputting a radio frequency signal, a second transistor, a third transistor for supplying a bias current, a first voltage supply circuit for supplying a lower voltage to a base of the third transistor as a temperature of a first diode is higher. The third transistor and the first transistor, or the third transistor and the second transistor, are disposed without another electronic element interposed therebetween. The third transistor is disposed such that a distance between the third transistor and the first transistor is smaller than a distance between the first voltage supply circuit and the first transistor, or a distance between the third transistor and the second transistor is smaller than a distance between the first voltage supply circuit and the second transistor.

Abstract: Provided is a high ruggedness HBT, including a first emitter cap layer and a second emitter cap layer formed between an emitter layer and an ohmic contact layer, or only an emitter cap layer is formed between them. When the first and second emitter cap layers are provided, bandgaps of the first or second emitter cap layer are changed, and the ruggedness of the HBT is improved. When an emitter cap layer is provided, an electron affinity of at least a portion of the emitter cap layer is less than or approximately equal to an electron affinity of the emitter layer, and the ruggedness of the HBT is improved.

Abstract: A bipolar junction transistor includes an extrinsic collector region buried in a semiconductor substrate under an intrinsic collector region. Carbon-containing passivating regions are provided to delimit the intrinsic collector region. An insulating layer on the intrinsic collector region includes an opening within which an extrinsic base region is provided. A semiconductor layer overlies the insulating layer, is in contact with the extrinsic base region, and includes an opening with insulated sidewalls. The collector region of the transistor is provided between the insulated sidewalls.

Abstract: On a single-crystal semiconductor substrate with an upper surface including a first direction in which an inverted mesa step extends and a second direction in which a forward mesa step extends in response to anisotropic etching in which an etching rate depends on crystal plane orientation, a bipolar transistor including a collector layer, a base layer, and an emitter layer that are epitaxially grown, and a base wire connected to the base layer are arranged. A step is provided at an edge of the base layer, and the base wire is extended from inside to outside of the base layer in a direction intersecting the first direction in a plan view. An intersection of the edge of the base layer and the base wire has a disconnection prevention structure that makes it difficult for step-caused disconnection of the base wire to occur.

Abstract: Structures for a heterojunction bipolar transistor and methods of fabricating such structures. A hardmask is formed that includes an opening over a first portion of a substrate in a first device region and a shape over a second portion of the substrate in a second device region. An oxidized region in the first portion of the substrate while the shape blocks oxidation of the second portion of the substrate. The oxidized region is subsequently removed from the first portion of the substrate to define a recess. A first base and a first emitter of a first heterojunction bipolar transistor are formed over the first portion of the substrate in the first device region, and a second base and a second emitter of a second heterojunction bipolar transistor are formed in the recess over the second portion of the substrate in the second device region.

Abstract: A thin Ge layer is formed between an SiGe intrinsic base and single-crystal Si extrinsic base structures to greatly simplify the fabrication of raised-base SiGe heterojunction bipolar transistors (HBTs). The fabrication process includes sequentially depositing the SiGe intrinsic base, the Ge, and Si extrinsic base layers as single-crystal structures over a patterned silicon wafer while the wafer is maintained inside a reaction chamber. The Ge layer subsequently functions as an etch stop, and protects the crystallinity of the underlying SiGe intrinsic base material during subsequent dry etching of the Si extrinsic base layer, which is performed to generate an emitter window. A wet etch then removes residual Ge from the emitter window to expose a contact portion of the SiGe layer surface without damage. A polysilicon emitter structure is formed in the emitter window, and then salicide is formed over the base stacks to encapsulate the SiGe and Ge structures.

Abstract: A semiconductor device includes a substrate, and a seed layer over the substrate, wherein the seed layer comprises carbon dopants. The semiconductor device further includes a channel layer over the seed layer, and an active layer over the channel layer, wherein the active layer has a band gap discontinuity with the channel layer. A method of making a transistor includes forming a seed layer over a substrate, and doping the seed layer, wherein doping the seed layer comprises introducing carbon dopants into the seed layer. The method further includes forming a channel layer over the seed layer, and forming an active layer over the channel layer, wherein the active layer has a band gap discontinuity with the channel layer.

Abstract: A compound semiconductor integrated circuit comprising a first substrate; a first electronic component formed on top of said first substrate; a layer of a first dielectric material formed on top of said first substrate and including said first electronic component, said layer of a first dielectric material comprising a recess exposing a first region of said first substrate; and a layer of a second dielectric material attached to said first substrate on top of said first region of said first substrate after manufacturing of said layer of a second dielectric material, said layer of a second material comprising a second electronic component.

Abstract: A semiconductor device comprising a bipolar transistor and a method of making the same. A power amplifier including a bipolar transistor. The bipolar transistor includes a collector including a laterally extending drift region. The also includes a base located above the collector. The bipolar transistor further includes an emitter located above the base. The bipolar transistor also includes a doped region having a conductivity type that is different to that of the collector. The doped region extends laterally beneath the collector to form a junction at a region of contact between the doped region and the collector. The doped region has a non-uniform lateral doping profile. A doping level of the doped region is highest in a part of the doped region closest to a collector-base junction of the bipolar transistor.

Abstract: Disclosed is a method of manufacturing an integrated circuit comprising a bipolar transistor, the method comprising providing a substrate (10) comprising a pair of first isolation regions (12) separated from each other by an active region (11) comprising a collector impurity said bipolar transistor; forming a base layer stack (14, 14?) over said substrate; forming a further stack of a migration layer (15) having a first migration temperature and an etch stop layer (20) over said base layer stack (14); forming a base contact layer (16) having a second migration temperature over the further stack, the second migration temperature being higher than the first migration temperature; etching an emitter window (28) in the base contact layer over the active region, said etching step terminating at the etch stop layer; at least partially removing the etch stop layer, thereby forming cavities (29) extending from the emitter window in between the base contact layer and the redistribution layer; and exposing the resultan

Abstract: A method of manufacturing an interposer is provided, including forming a plurality of first openings on one surface side of a substrate, forming a first metal layer in the first openings, forming on the other surface side of the substrate a plurality of second openings that are in communication with the first openings, forming a second metal layer in the second openings, and electrically connecting the first metal layer to the second metal layer, so as to form conductive through holes. The conductive through holes are formed stage by stage, such that the fabrication time in forming the metal layers is reduced, and a metal material will not be accumulated too thick on a surface of the substrate. Therefore, the metal material has a smoother surface, and no overburden will be formed around end surfaces of the through holes. An interposer is also provided.

Abstract: A segmented bipolar transistor includes a p-base in a semiconductor surface including at least one p-base finger having a base metal/silicide stack including a base metal line that contacts a silicide layer on the semiconductor surface of the p-base finger. An n+ buried layer is under the p-base. A collector includes an n+ sinker extending from the semiconductor surface to the n+ buried layer including a collector finger having a collector metal/silicide stack including a collector metal line that contacts a silicide layer on the semiconductor surface of the collector finger. An n+ emitter has at least one emitter finger including an emitter metal/silicide stack that contacts the silicide layer on the semiconductor surface of the emitter finger. The emitter metal/silicide stack and/or collector metal/silicide stack include segmentation with a gap which cuts a metal line and/or the silicide layer of the stack.

Abstract: A method of forming a non-volatile memory device, includes providing a substrate, forming a first dielectric over the substrate, forming a first wiring structure over the first dielectric, forming a first conductor in contact with the first wiring structure, forming a polycrystalline p+ SiGe material over the first conductor at a deposition temperature ranging from about 350 to about 500 Degrees Celsius, forming a polycrystalline silicon conformally over the SiGe material using the SiGe material as a lattice template at a deposition temperature within about 350 to about 500 Degrees Celsius, the polycrystalline silicon having an intrinsic semiconductor characteristic, forming a second conductor over the polycrystalline silicon in physical and electric contact with the resistive polycrystalline silicon, and forming a second wiring structure over the second conductor.

Abstract: A heterojunction bipolar transistor (HBT) structure, method of manufacturing the same and design structure thereof are provided. The HBT structure includes a semiconductor substrate having a sub-collector region therein. The HBT structure further includes a collector region overlying a portion of the sub-collector region. The HBT structure further includes an intrinsic base layer overlying at least a portion of the collector region. The HBT structure further includes an extrinsic base layer adjacent to and electrically connected to the intrinsic base layer. The HBT structure further includes an isolation region extending vertically between the extrinsic base layer and the sub-collector region. The HBT structure further includes an emitter overlying a portion of the intrinsic base layer. The HBT structure further includes a collector contact electrically connected to the sub-collector region. The collector contact advantageously extends through at least a portion of the extrinsic base layer.

Abstract: Disclosed are devices and methods of forming the devices wherein pair(s) of first openings are formed through a dielectric layer and a first semiconductor layer into a substrate and, within the substrate, the first openings of each pair are expanded laterally and merged to form a corresponding trench. Dielectric material is deposited, filling the upper portions of the first openings and creating trench isolation region(s). A second semiconductor layer is deposited and second opening(s) are formed through the second semiconductor and dielectric layers, exposing monocrystalline portion(s) of the first semiconductor layer between the each pair of first openings. A third semiconductor layer is epitaxially deposited with a polycrystalline section on the second semiconductor layer and monocrystalline section(s) on the exposed monocrystalline portion(s) of the first semiconductor layer. A crystallization anneal is performed and a device (e.g.

Abstract: Fabrication methods for a bipolar junction transistor. A semiconductor material layer is formed on a substrate and a mask layer is formed on the semiconductor material layer. The mask layer is patterned to form a plurality of openings to the semiconductor material layer. After the mask layer is formed and patterned, the semiconductor material layer is etched at respective locations of the openings to define a first trench, a second trench separated from the first trench by a first section of the semiconductor material layer defining a terminal of the bipolar junction transistor, and a third trench separated from the first trench by a second section of the semiconductor material layer defining an isolation pedestal. A trench isolation region is formed at a location in the substrate that is determined at least in part using the isolation pedestal as a positional reference.

Abstract: A method of forming the heterojunction bipolar transistor that includes providing a stack of a base layer, an extrinsic base layer, a first metal containing layer, and a dielectric cap layer. The dielectric cap layer and the first metal containing layer may be etched to provide a base contact and a dielectric cap. Exposed portions of the base layer may be etched selectively to the dielectric cap. A remaining portion of the base layer provides the base region. A hydrogenated silicon containing layer may be deposited with a low temperature deposition method. At least a portion of the hydrogenated silicon containing layer is formed on at least sidewalls of the base region. A second metal containing layer may be formed on the hydrogenated silicon containing layer. The second metal containing and the hydrogenated silicon containing layer may be etched to provide an emitter region and a collector region.

Abstract: Consistent with an example embodiment, a GaN heterojunction structure has a three-layer dielectric structure. The lowermost and middle portions of the gate electrode together define the gate foot, and this is associated with two dielectric layers. A thinner first dielectric layer is adjacent the gate edge at the bottom of the gate electrode. The second dielectriclayer corresponds to the layer in the conventional structure, and it is level with the main portion of the gate foot.

Abstract: Methods of manufacture of advanced electronic and photonic structures including heterojunction transistors, transistor lasers and solar cells and their related structures, are described herein. Other embodiments are also disclosed herein.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. An intrinsic base is formed on the substrate, a terminal is formed on the intrinsic base, and an extrinsic base is formed that is arranged in juxtaposition with the intrinsic base on the substrate. The intrinsic base and terminal are respectively comprised of first and second semiconductor materials.

Abstract: Portions of a top compound semiconductor layer are recessed employing a gate electrode as an etch mask to form a source trench and a drain trench. A low temperature epitaxy process is employed to deposit a semiconductor material including at least one elemental semiconductor material in the source trench and the drain trench. Metallization is performed on physically exposed surfaces of the elemental semiconductor material portions in the source trench and the drain trench by depositing a metal and inducing interaction with the metal and the at least one elemental semiconductor material. A metal semiconductor alloy of the metal and the at least one elemental semiconductor material can be performed at a temperature lower than 600° C. to provide a high electron mobility transistor with a well-defined device profile and reliable metallization contacts.

Abstract: A III-nitride switch includes a recessed gate contact to produce a nominally off, or an enhancement mode, device. By providing a recessed gate contact, a conduction channel formed at the interface of two III-nitride materials is interrupted when the gate electrode is inactive to prevent current flow in the device. The gate electrode can be a schottky contact or an insulated metal contact. Two gate electrodes can be provided to form a bi-directional switch with nominally off characteristics. The recesses formed with the gate electrode can have sloped sides. The gate electrodes can be formed in a number of geometries in conjunction with current carrying electrodes of the device.

Abstract: Disclosed is an integrated circuit and a method of manufacturing an integrated circuit comprising a bipolar transistor, the method comprising providing a substrate comprising a pair of isolation regions separated by an active region comprising a collector; forming a base layer stack over said substrate; forming a migration layer having a first migration temperature and an etch stop layer; forming a base contact layer having a second migration temperature; etching an emitter window in the base contact layer, thereby forming cavities extending from the emitter window; and exposing the resultant structure to the first migration temperature in a hydrogen atmosphere, thereby filling the cavities with the migration layer material.

Abstract: A silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) is disclosed, including: a substrate; two field oxide regions formed in the substrate; two pseudo buried layers, each being formed under a corresponding one of the field oxide regions; a collector region formed between the field oxide regions, the collector region laterally extending under a corresponding one of the field oxide regions and each side of the collector region being connected with a corresponding one of the pseudo buried layers; a matching layer formed under both the pseudo buried layers and the collector region; and two deep hole electrodes, each being formed in a corresponding one of the field oxide regions, the deep hole electrodes being connected to the corresponding ones of the pseudo buried layers for picking up the collector region. A manufacturing method of the SiGe HBT is also disclosed.

Abstract: A heterojunction bipolar transistor (HBT), an integrated circuit (IC) chip including at least one HBT and a method of forming the IC. The HBT includes an extrinsic base with one or more buried interstitial barrier layer. The extrinsic base may be heavily doped with boron and each buried interstitial barrier layer is doped with a dopant containing carbon, e.g., carbon or SiGe:C. The surface of the extrinsic base may be silicided.

Abstract: Disclosed is a transistor structure, having a completely silicided extrinsic base for reduced base resistance Rb. Specifically, a metal silicide layer covers the extrinsic base, including the portion of the extrinsic base that extends below the upper portion of a T-shaped emitter. One exemplary technique for ensuring that the metal silicide layer covers this portion of the extrinsic base requires tapering the upper portion of the emitter. Such tapering allows a sacrificial layer below the upper portion of the emitter to be completely removed during processing, thereby exposing the extrinsic base below and allowing the metal layer required for silicidation to be deposited thereon. This metal layer can be deposited, for example, using a high pressure sputtering technique to ensure that all exposed surfaces of the extrinsic base, even those below the upper portion of the emitter, are covered.

Abstract: A graphene base transistor with reduced collector area comprising an electron injection region, an electron collection region, and a base region wherein the base region comprises one or more sheets of graphene and wherein the base region is intermediate the electron injection region and the electron collection region and forms electrical interfaces therewith. A method of making a graphene base transistor with reduced collector area comprising forming an electron injection region, forming an electron collection region, and forming a base region wherein the base region comprises one or more sheets of graphene and wherein the base region is intermediate the electron injection region and the electron collection region and forms electrical interfaces therewith.

Abstract: A thin-film transistor device includes: a gate electrode above a substrate; a gate insulating film on the gate electrode; a crystalline silicon thin film above the gate insulating film; a first semiconductor film above the crystalline silicon thin film; a pair of second semiconductor films above the first semiconductor film; a source electrode over one of the second semiconductor films; and a drain electrode over an other one of the second semiconductor films. The first semiconductor film is provided on the crystalline silicon thin film. A relationship ECP<EC1 is satisfied where ECP and EC1 denote energy levels at lower ends of conduction bands of the crystalline silicon thin film and the first semiconductor film, respectively.

Abstract: Methods of manufacture of advanced heterojunction transistors and transistor lasers, and their related structures, are described herein. Other embodiments are also disclosed herein.

Abstract: A bipolar device with an entirely monocrystalline intrinsic base to extrinsic base link-up region. To form the device, a first extrinsic base layer, which is amorphous or polycrystalline, is deposited such that it contacts an edge portion of a monocrystalline section of an intrinsic base layer through an opening in a dielectric layer. A second extrinsic base layer is deposited on the first. An anneal is performed, either before or after deposition of the second extrinsic base layer, so that the extrinsic base layers are monocrystalline. An opening is formed through the extrinsic base layers to a dielectric landing pad aligned above a center portion of the monocrystalline section of the intrinsic base layer. The dielectric landing pad is removed and a semiconductor layer is grown epitaxially on exposed monocrystalline surfaces of the extrinsic and intrinsic base layers, thereby forming the entirely monocrystalline intrinsic base to extrinsic base link-up region.

Abstract: An exemplary embodiment of the present invention provides a heterojunction bipolar transistor comprising an emitter, a collector, and a base. The base can be disposed substantially between the emitter and collector. The base can comprise a plurality of alternating type-I and type-II layers arranged to form a short period super lattice. The type-I layers can have a band-gap that is narrower than the band-gap of the type-II layers. At least one of the type-I layers and the type-II layers can consist essentially of a quaternary material.

Abstract: A semiconductor device includes: a board; a power wire formed on the board; a signal wire formed on the board; a ground wire formed on the board; an insulating layer covering the signal wire, the power wire and the ground wire; and a metal film formed on the insulating layer, wherein a thickness of the insulating layer covering the power wire is different from a thickness of the insulating layer covering the signal wire, and the metal film is connected to a ground potential.

Abstract: Disclosed are example bipolar transistors capable of reducing the area of a collector, reducing the distance between a base and a collector, and/or reducing the number of ion implantation processes. A bipolar transistor may includes a trench formed by etching a portion of a semiconductor substrate. A first collector may be formed on the inner wall of the trench. A second collector may be formed inside the semiconductor substrate in the inner wall of the trench. A first isolation film may be formed on the sidewall of the first collector. An intrinsic base may be connected to the third collector. An extrinsic base may be formed on the intrinsic base and inside the first isolation film. A second isolation film may be formed on the inner wall of the extrinsic base. An emitter may be formed by burying a conductive material inside the second isolation film.

Abstract: An NPN bipolar junction transistor is disclosed that exhibits a collector-to-emitter breakdown voltage greater than 10 volts and a beta greater than 300. The large value of beta is obtained by fabricating the transistor with an extra N-type layer that reduces recombination of electrons and holes.

Abstract: A dielectric stack and method of depositing the stack to a substrate using a single step deposition process. The dielectric stack includes a dense layer and a porous layer of the same elemental compound with different compositional atomic percentage, density, and porosity. The stack enhances mechanical modulus strength and enhances oxidation and copper diffusion barrier properties. The dielectric stack has inorganic or hybrid inorganic-organic random three-dimensional covalent bonding throughout the network, which contain different regions of different chemical compositions such as a cap component adjacent to a low-k component of the same type of material but with higher porosity.

Abstract: Trench-confined selective epitaxial growth process in which epitaxial growth of a semiconductor device layer proceeds within the confines of a trench. In embodiments, a trench is fabricated to include a pristine, planar semiconductor seeding surface disposed at the bottom of the trench. Semiconductor regions around the seeding surface may be recessed relative to the seeding surface with Isolation dielectric disposed there on to surround the semiconductor seeding layer and form the trench. In embodiments to form the trench, a sacrificial hardmask fin may be covered in dielectric which is then planarized to expose the hardmask fin, which is then removed to expose the seeding surface. A semiconductor device layer is formed from the seeding surface through selective heteroepitaxy. In embodiments, non-planar devices are formed from the semiconductor device layer by recessing a top surface of the isolation dielectric.

Abstract: The present invention discloses a metal silicide self-aligned SiGe heterojunction bipolar transistor, which is designed to overcome the shortcomings such as the large base resistance RB of the prior art products. The metal silicide self-aligned SiGe heterojunction bipolar transistor of the present invention mainly comprises an Si collector region, a local dielectric region, a base region, a base-region low-resistance metal silicide layer, a polysilicon emitter region, an emitter-base spacer dielectric region composed of a liner silicon oxide layer and a silicon nitride inner sidewall, a monocrystalline emitter region, a contact hole dielectric layer, an emitter metal electrode and a base metal electrode. The base-region low-resistance metal silicide layer extends all the way to the outside of the emitter-base spacer dielectric region. The present invention discloses a method of forming a metal silicide self-aligned SiGe heterojunction bipolar transistor, which is used to form the aforesaid bipolar transistor.

Abstract: In a semiconductor chip in which LDMOSFET elements for power amplifier circuits used for a power amplifier module are formed, a source bump electrode is disposed on an LDMOSFET formation region in which a plurality of source regions, a plurality of drain regions and a plurality of gate electrodes for the LDMOSFET elements are formed. The source bump electrode is formed on a source pad mainly made of aluminum via a source conductor layer which is thicker than the source pad and mainly made of copper. No resin film is interposed between the source bump electrode and the source conductor layer.

Abstract: A power SiGe heterojunction bipolor transistor (HBT) with improved drive current by strain compensation and methods of manufacture are provided. A method includes adding carbon in a continuous steady concentration in layers of a device including a subcollector layer, a collector layer, a base buffer layer, a base layer, and an emitter buffer layer.

Abstract: A high-quality GaAs-type crystal thin film using an inexpensive Si wafer with good thermal release characteristics is achieved. Provided is a semiconductor wafer comprising an Si wafer; an inhibiting layer that is formed on the wafer and that inhibits crystal growth, the inhibiting layer including a covering region that covers a portion of the wafer and an open region that does not cover a portion of the wafer within the covering region; a Ge layer that is crystal-grown in the open region; and a functional layer that is crystal-grown on the Ge layer. The Ge layer may be formed by annealing with a temperature and duration that enables movement of crystal defects, and the annealing is repeated a plurality of times.

Abstract: A heterojunction transistor including a semiconductor body is provided. The semiconductor body includes: a base region of a semiconductor material having a first band-gap, the base region being of a first conductivity type; a collector region of a semiconductor material having a second band-gap which is larger than the first band-gap by at least about 1 eV, the collector region being of a second conductivity type and forming a first heterojunction with the base region; and an emitter region of a semiconductor material having a third band-gap which is larger than the first band-gap by at least about 1 eV, the emitter region being of the second conductivity type and forming a second heterojunction with the base region. Further, a method for producing a heterojunction transistor is provided.

Abstract: A bipolar transistor is fabricated having a collector (52) in a substrate (1) and a base (57, 58) and an emitter (59) formed over the substrate. The base has a stack region (57) which is laterally separated from the emitter (59) by an electrically insulating spacer (71). The insulating spacer (71) has a width dimension at its top end at least as large as the width dimension at its bottom end and forms a ?-shape or an oblique shape. The profile reduces the risk of silicide bridging at the top of the spacer in subsequent processing, while maintaining the width of emitter window.

Abstract: A method of fabricating a substrate includes forming spaced first features and spaced second features over a substrate. The first and second features alternate with one another and are spaced relative one another. Width of the spaced second features is laterally trimmed to a greater degree than any lateral trimming of width of the spaced first features while laterally trimming width of the spaced second features. After laterally trimming of the second features, spacers are formed on sidewalls of the spaced first features and on sidewalls of the spaced second features. The spacers are of some different composition from that of the spaced first features and from that of the spaced second features. After forming the spacers, the spaced first features and the spaced second features are removed from the substrate. The substrate is processed through a mask pattern comprising the spacers. Other embodiments are disclosed.

Abstract: A semiconductor structure is disclosed. The semiconductor structure includes a first layer. A second layer is disposed on the first layer and different from the first layer in composition. An interface is between the first layer and the second layer. A third layer is disposed on the second layer. A gate is disposed on the third layer. A source feature and a drain feature are disposed on opposite sides of the gate. Each of the source feature and the drain feature includes a corresponding metal feature at least partially embedded in the second and the third layer. A corresponding intermetallic compound underlies each metal feature. Each intermetallic compound contacts a carrier channel located at the interface.

Abstract: A wafer comprising at least one emitter-up Heterojunction Bipolar Transistor (HBT) and at least one emitter-down HBT on a common InP based semiconductor wafer. Isolation and N-type implants into the device layers differentiate an emitter-down HBT from an emitter-up HBT. The method for preparing a device comprises forming identical layers for all HBTs and performing ion implantation to differentiate an emitter-down HBT from an emitter-up HBT.