Abstract: A bipolar transistor with a SiGe:C film and a seed layer forming beneath the SiGe:C film and methods of making same. The method includes placing a substrate in a reactor chamber and introducing a silicon source gas into the reactor chamber to form a silicon seed layer. The reactor chamber is maintained at a pressure below 45 Torr and a temperature between about 700° C. and 850° C. After the seed layer is formed, the silicon source gas is stopped. The reactor chamber is then simultaneously adjusted to a pressure between about 70 Torr and 90 Torr and a temperature between about 600° C. and 650° C. The silicon source gas, a germanium source gas, and a carbon source gas are introduced to form the SiGe:C film on the seed layer.

Abstract: A thin InGaAs contact layer is provided for the collector of a heterojunction bipolar transistor (HBT) above an InP sub-collector. The contact layer provides a low resistance contact mechanism and a high thermal conductivity path for removing device heat though the sub-collector, and also serves as an etch stop to protect the sub-collector during device fabrication. A portion of the sub-collector lateral to the remainder of the HBT is rendered electrically insulative, preferably by an ion implant, to provide electrical isolation for the device and improve its planarity by avoiding etching through the sub-collector.

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

Abstract: A bipolar heterojunction transistor (HBT) includes a collector layer, a base layer formed on the collector layer, a first transition layer formed on the base layer, an emitter layer formed on the first transition layer, a second transition layer formed on the emitter layer, and an emitter cap layer formed on the second transition layer. Each of the first and second transition layers is formed of a composition that contains an element, the mole fraction of which is graded in such a manner that the conduction band of the HBT is continuous through the base layer, the first and second transition layers, the emitter layer and the emitter cap layer.

Abstract: A method for fabrication of defect-free epitaxial layers on top of a surface of a first defect-containing solid state material includes the steps of selective deposition of a second material, having a high temperature stability, on defect-free regions of the first solid state material, followed by subsequent evaporation of the regions in the vicinity of the defects, and subsequent overgrowth by a third material forming a defect-free layer.

Abstract: A method for forming a heterojunction bipolar transistor includes forming an epitaxial layer, forming a first polysilicon layer, and forming a dielectric layer on the first polysilicon layer. The first polysilicon layer and the dielectric layer include an opening for exposing a portion of the top surface of the epitaxial layer. Then, a silicon germanium layer is selectively grown in the opening. The silicon germanium layer is grown on the exposed top surface of the epitaxial layer and on the exposed sidewall of the first polysilicon layer. Next, a spacer is formed along the sidewalls of the dielectric layer and the silicon germanium layer. A second polysilicon layer in electrical contact with the silicon germanium layer is then formed. Accordingly, a low resistance connection between the first polysilicon layer forming the extrinsic base region and the silicon germanium layer forming the intrinsic base region of the transistor is formed.

Abstract: When InP DHBTs are located in parallel to a crystallographical direction of <011>, there are several advantages in the aspect of device property such as reliability. But, in case of a direction parallel to a general <011>, there exists the limitation in reducing base-collector parasitic capacitance only by collector over-etching technique due to poor lateral-etching characteristic of the InP collector. To overcome such a problem mentioned above and improve device performance, the present invention provides a method of reducing parasitic capacitance using underneath crystallographically selective wet etching, thereby providing a self-alignable, structurally stable device.

Abstract: A method of fabricating a high-performance, raised extrinsic base HBT having a narrow emitter width is provided. In accordance with the method, a patterned nitride pedestal region and inner spacers are employed to reduce the width of an emitter opening. The reduced width is achieved without the need of using advanced lithographic tools and/or advanced photomasks.

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

Abstract: An Si/SiGe layer including an Si buffer layer, an SiGe spacer layer, a graded SiGe layer and an Si cap layer is epitaxially grown in a region corresponding to a collector opening while a polycrystalline layer is deposited on the upper surface of a nitride film, and side surfaces of an oxide film and the nitride film. In this case, the Si buffer layer is formed first and then other layers such as the SiGe spacer layer are formed, thereby ensuring non-selective epitaxial growth. Then, a polycrystalline layer is deposited over the nitride film.

Abstract: A structure and method of making an NPN heterojunction bipolar transistor (100) includes a semiconductor substrate (11) with a first region (82) containing a dopant (86) for forming a base region of the transistor. A second region (84) adjacent to the first region is used to form an emitter region of the transistor. An interstitial trapping material (81) reduces diffusion of dopants in the base region during subsequent thermal processing.

Abstract: An Si/SiGe layer including an Si buffer layer, an SiGe spacer layer, a graded SiGe layer and an Si cap layer is epitaxially grown in a region corresponding to a collector opening while a polycrystalline layer is deposited on the upper surface of a nitride film, and side surfaces of an oxide film and the nitride film. In this case, the Si buffer layer is formed first and then other layers such as the SiGe spacer layer are formed, thereby ensuring non-selective epitaxial growth. Then, a polycrystalline layer is deposited over the nitride film.

Abstract: The present disclosure provides a method for forming and manufacturing a silicon germanium (SiGe) based device. After forming a substrate of the device and forming one or more layers of semiconductor processing materials in one or more predetermined locations to establish an opening for depositing one or more SiGe material layers, a pre-baking process is applied to the device under a low pressure not to exceed 79 torr and 900° C. Once completed, the one or more SiGe material layers are deposited and other conventional steps are taken to complete the manufacturing of the device.

Abstract: According to one disclosed embodiment, a transistor gate is fabricated on a substrate. For example, the gate can be a polycrystalline silicon gate in a FET. Thereafter, a conformal layer is deposited over the substrate and the gate and is then etched back to form spacers on the sides of the gate. An underlying dielectric layer is formed on the substrate, gate, and spacers. The conformal layer and the underlying dielectric layer can be comprised of, for example, a dielectric such as silicon dioxide, silicon nitride, or a low-k dielectric. Next, an overcoat layer is fabricated on the underlying dielectric layer. The overcoat layer can be, for example, polycrystalline silicon. Following, an opening is etched in the overcoat layer and the underlying dielectric layer wherein subsequent films can be grown. For example, silicon germanium can be grown in the opening for fabrication of a silicon germanium heterojunction bipolar transistor.

Abstract: A structure and method of making an NPN heterojunction bipolar transistor (100) includes a semiconductor substrate (11) with a first region (82) containing a dopant (86) for forming a base region of the transistor. A second region (84) adjacent to the first region is used to form an emitter region of the transistor. An interstitial trapping material (81) reduces diffusion of dopants in the base region during subsequent thermal processing.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as SiC or sapphire by forming a compliant substrate for the growing the monocrystalline layers. Devices and methods for fabricating silicon carbide based heterojunction bipolar devices such as transistors and diodes. These devices are suitable for high power and/or high speed and/or high temperature electronic applications.

Abstract: A method of fabricating high-quality, substantially relaxed SiGe-on-insulator substrate is provided by implanting oxygen into a Si/SiGe multilayer heterostructure which comprises alternating Si and SiGe layers. Specifically, the high quality, relaxed SiGe-on-insulator is formed by implanting oxygen ions into a multilayer heterostructure which includes alternating layers of Si and SiGe. Following, the implanting step, the multilayer heterostructure containing implanted oxygen ions is annealed, i.e., heated, so as to form a buried oxide region predominately within one of the Si layers of the multilayer structure.

Abstract: A bipolar transistor device with a large current capacity is formed by connecting a plurality of transistor elements to each other in parallel, each transistor element having a collector layer, a base layer, and an emitter layer formed respectively in a semiconductor substrate. In the bipolar transistor device, the base layers of a plurality of the transistor elements are extended in parallel to each other and those base layers are separated from each other. In each separated base layer, a first base electrode is formed on a part of the base layer which is separated from an emitter junction with the emitter layer, and a second base electrode is formed on another portion of the base layer closer to the emitter junction than the first base electrode. To dispose the base electrodes of a plurality of the transistor elements in parallel to each other, a base wiring is connected to the first base electrodes of those elements electrically.

Abstract: The method according to the invention makes it possible to fabricate a bipolar transistor with a low base connection resistance, low defect density and improved scalability. Scalability is to be understood in this case as both the lateral scaling of the emitter window and the vertical scaling of the base width (low temperature budget). The temperature budget can be kept low in the base region since no implantations are required in order to reduce the base connection resistance. Furthermore, the difficulties associated with the point defects are largely avoided.

Abstract: The aim of the invention is to provide for a bipolar transistor and a method for producing the same. Said bipolar transistor should have minimal base-emitter capacities and very good high frequency characteristics. The static characteristics, especially the base current ideality and the low frequency noise, of a bipolar transistor with weakly doped cap layer (116) should not significantly deteriorate and process complexity should not increase. According to the invention, the problem is solved by inserting a special doping profile in a cap layer (116) (cap doping) which has been produced epitaxially. A minimal base emitter capacity and very good high frequency characteristics can be obtained by means of said doping profile. At the same time, the efficiency of the generation/recombination active boundary surface between the cap layer (116) and the isolator (117) in the polysilicon overlapping area in the relevant working area of the transistor is reduced and the base current ideality is improved.

Abstract: The present invention proposes a novel method to fabricate a Bipolar Junction Transistor device. The steps of the present invention include forming a shallow trench isolation structure in a substrate. An oxide layer is formed on the substrate. Subsequently, a polysilicon layer is next formed on the oxide layer, and the polysilicon layer has first type ion. Successively, a polysilicon layer is patterned on the oxide layer. The next step is to perform a second type ion implantation, thereby forming a collector region in the substrate and below the emitter window. The oxide layer is removed inside the emitter window. An expitaxy base is then formed on the polysilicon layer and substrate, thereby forming base region on the collector region, wherein the expitaxy base has the first type ion. After the expitaxy base is formed, a dielectric layer is formed over the expitaxy base. Next, the dielectric layer is etched to form inner spacer on sidewalls of the expitaxy base inside the emitter window.

Abstract: A semiconductor structure and a method of forming same is disclosed. The method includes forming, on a substrate, an n-doped collector structure of InAs/AlSb materials; forming a base structure on said collector structure which base structure comprises p-doped GaSb; and forming, on said base structure, an n-doped emitter structure of InAs/AlSb materials. The collector and emitter structure are preferably superlattices each comprising a plurality of periods of InAs and AlSb sublayers. A heterojunction bipolar transistor manufactured using the method is disclosed.

Abstract: The vertical bipolar transistor includes an SiGe heterojunction base formed by a stack of layers of silicon and silicon-germanium resting on an initial layer of silicon nitride extending over a side insulation region surrounding the upper part of the intrinsic collector. The stack of layers also extends on the surface of the intrinsic collector which lies inside a window formed in the initial layer of silicon nitride.

Abstract: The present invention achieves the enhancement of a manufacturing yield factor and the reduction of manufacturing cost in a manufacturing method of a semiconductor device having a hetero junction bipolar transistor (HBT), a Schottky diode and a resistance element. The present invention is directed to the manufacturing method of a semiconductor device in which respective semiconductor layers which become a sub collector layer, a collector layer, a base layer, a wide gap emitter layer and an emitter layer are sequentially formed over one surface of a semiconductor substrate and, thereafter, respective semiconductor layers are processed to form the hetero junction bipolar transistor, the Schottky diode and the resistance element in a monolithic manner. An emitter electrode of the hetero junction bipolar transistor, a Schottky electrode of the Schottky diode and a resistance film of the resistance element are simultaneously formed using a same material (for example, WSiN).

Abstract: A method of fabricating a SiGe heterojunction bipolar transistor (HBT) is provided which results in a SiGe HBT that has a controllable current gain and improved breakdown voltage. The SiGe HBT having these characteristics is fabricated by forming an in-situ P-doped emitter layer atop a patterned SiGe base structure. The in-situ P-doped emitter layer is a bilayer of in-situ P-doped a:Si and in-situ P-doped polysilicon. The SiGe HBT structure including the above mentioned bilayer emitter is also described herein.

Abstract: On a multilayer film which is formed on a semiconductor substrate, an opening which is opened on a base and an emitter is formed in the multilayer film, and after an SiGe/SiGeC film, which has a composition with a higher content of Si in an upper layer region and a lower layer region, and a higher content of Ge in an intermediate layer region, is formed on an entire surface, anisotropic dry etching is performed for the SiGe/SiGeC film up to a predetermined height of the opening.

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

Abstract: Embodiments of a bipolar transistor are disclosed, along with methods for making the transistor. An exemplary transistor includes a collector region in a semiconductor substrate, a base layer overlying the collector region and bound by a field oxide layer, a dielectric isolation layer overlying the base layer, and an emitter structure overlying the dielectric isolation layer and contacting the base layer through a central aperture in the dielectric layer. The transistor may be a heterojunction bipolar transistor with the base layer formed of a selectively grown silicon germanium alloy. A dielectric spacer may be formed adjacent the emitter structure and over a portion of the base layer.

Abstract: Embodiments of a bipolar transistor are disclosed, along with methods for making the transistor. An exemplary transistor includes a collector region in a semiconductor substrate, a base layer overlying the collector region and bound by a field oxide layer, a dielectric isolation layer overlying the base layer, and an emitter structure overlying the dielectric isolation layer and contacting the base layer through a central aperture in the dielectric layer. The transistor may be a heterojunction bipolar transistor with the base layer formed of a selectively grown silicon germanium alloy. A dielectric spacer may be formed adjacent the emitter structure and over a portion of the base layer.

Abstract: A heterojunction bipolar transistor includes an emitter layer, a base layer and a collector layer laminated on a top surface of a semiconductor substrate, and a heat sink layer made of a metal and provided on a rear surface of the substrate. A via hole is cut through the emitter layer, the base layer, the collector layer and the substrate. A surface electrode of the emitter layer and the heat sink layer are connected to each other by a metal wiring line running through within the via hole, which is capable of improving the heat radiation and reducing the emitter inductance.

Abstract: The invention relates to the protection of devices in a monolithic chip fabricated from an epitaxial wafer, such as a wafer for a Group III-V compound semiconductor or a wafer for a Group IV compound semiconductor. Devices fabricated from Group III-V compound semiconductors offer higher speed and better isolation than comparable devices from silicon semiconductors. Semiconductor devices can be permanently damaged when exposed to an undesired voltage transient such as electrostatic discharge (ESD). However, conventional techniques developed for silicon devices are not compatible with processing techniques for Group III-V compound semiconductors, such as gallium arsenide (GaAs). Embodiments of the invention advantageously include transient voltage protection circuits that are relatively efficiently and reliably manufactured to protect sensitive devices from undesired voltage transients.

Abstract: A heterojunction bipolar transistor is doped in the sub-collector layer (20) with phosphorus (24). The presence of the phosphorus causes any interstitial gallium (22) to be bonded (26) to the phosphorus (24) and move to a lattice site. The result is that the interstitial gallium does not diffuse to the base layer and thus does not cause the beryllium to be displaced and diffused. Instead of doping with phosphorus, a layer including phosphorus can also be utilized.

Abstract: According to one exemplary embodiment, a heterojunction bipolar transistor comprises a base having a top surface. The heterojunction bipolar transistor further comprises an epitaxial emitter selectively situated on the top surface of the base. For example, the epitaxial emitter may be N-type single-crystal silicon. The heterojunction bipolar transistor further comprises an etch stop layer situated on the top surface of the base, where the etch stop layer is in contact with the epitaxial emitter. The heterojunction bipolar transistor further comprises a first spacer and a second spacer situated on the etch stop layer, where the epitaxial emitter is situated between the first and second spacer. The first spacer and the second spacer, for example, may be LPCVD silicon nitride. The heterojunction bipolar transistor further comprises a dielectric layer deposited on the first and second spacers.

Abstract: A semiconductor device includes a SiGe base bipolar transistor. The SiGe base bipolar transistor includes an emitter layer, a collector layer and a SiGe base layer formed of silicon containing germanium. A Ge concentration of the SiGe base layer is increased from 0% to 10% from a side of the emitter layer towards a side of the collector layer.

Abstract: According to one exemplary embodiment, a heterojunction bipolar transistor comprises a base having a concentration of germanium, where the concentration of germanium decreases between a first depth and a second depth in the base. According to this exemplary embodiment, the base of the heterojunction bipolar transistor further comprises a concentration of a diffusion suppressant of a base dopant, where the concentration of the diffusion suppressant decreases between a third depth and a fourth depth so as to counteract a change in band gap in the base between the first depth and the second depth. For example, the diffusion suppressant can be carbon and the base dopant can be boron. For example, the concentration of diffusion suppressant may decrease between the third depth and fourth depth so as to counteract the change in band gap at approximately the second depth.

Abstract: According to one disclosed embodiment, a heavily doped subcollector is formed. Subsequently, a collector is fabricated over the heavily-doped subcollectoi, wherein the collector comprises a medium-doped collector layer adjacent to the subcollector and a low-doped collector layer over the medium-doped collector layer. Both the medium-doped collector layer and the low-doped collector layer can comprise gallium-arsenide doped with silicon at between approximately 5×1016 cm−3 and approximately 1×1018 cm−3, and at between approximately 1×1016 cm−3 and approximately 3×1016 cm−3, respectively. Thereafter, a base is grown over the collector, and an emitter is deposited over the base. The collector of the HBT prevents the depletion region from reaching the subcollector without unduly impeding the expansion of the depletion region. As a result, filamentation in the subcollector is prevented, but the HBT's performance remains optimal.

Abstract: A transistor structure is implemented which can achieve high current gain by causing electrons injected from an emitter to reach a collector. An InGaN graded layer, which is interposed between a p-type InGaN layer and an n-type GaN layer, includes an In composition that varies from 0% to 10%. A bandgap of the thin film structure is gradually reduced from the substrate side to the surface side. An AlN buffer layer is grown on an SiC substrate by 100 nm thick, followed by growing a Si-doped GaN layer used for forming an ohmic electrode. A Si-doped GaN layer (n-type GaN layer) is grown thereon, followed by growing an InGaN layer whose In composition is varied, and by growing, an Mg-doped InGaN (p-type GaN layer), thereby fabricating a heterojunction diode.

Abstract: This invention provides a method for manufacturing a hetero-junction bipolar transistor, in which a hole concentration of a base layer doped with carbon can be increased. The method comprises the following steps. 1) A sub-collector 30, a collector 50, a base 60 doped with carbon are sequentially grown after setting a semiconductor substrate on the stage in the growth chamber; 2) an emitter 70 and an emitter contact 80 are grown at a temperature T; and 3) grown layers are annealed at a temperature TA, where the relation of T<Ta≦600° is satisfied. This process enhances the activation of carbon atoms by dissociating hydrogen atoms captured in the base 60 to the ambience.

Abstract: A heterojunction bipolar transistor is provided having an improved current gain cutoff frequency. The heterojunction bipolar transistor includes a contact region formed from InGaAsSb. The contact region allows an emitter region of the heterojunction bipolar transistor to realize a lower contact resistance value to yield an improved cutoff frequency (fT).

Abstract: A method for fabricating a heterojunction bipolar transistor having collector, base and emitter regions is disclosed. In an exemplary embodiment of the invention, the method includes forming a silicon epitaxial layer upon a substrate, the silicon epitaxial layer defining the collector region. An oxide stack is formed upon the silicon epitaxial layer and a nitride layer is then formed upon the oxide stack. Next, an emitter opening is defined within the nitride layer before a base cavity is formed within the oxide stack. The base cavity extends laterally beyond the width of the emitter opening. A silicon-germanium epitaxial layer is grown within the base cavity, the silicon-germanium epitaxial layer defining the base region. Finally, a polysilicon layer is deposited upon said silicon-germanium epitaxial layer, the polysilicon layer defining the emitter region.

Abstract: A method of fabricating a SiGe heterojunction bipolar transistor (HBT) is provided which results in a SiGe HBT that has a controllable current gain and improved breakdown voltage. The SiGe HBT having these characteristics is fabricated by forming an in-situ P-doped emitter layer atop a patterned SiGe base structure. The in-situ P-doped emitter layer is a bilayer of in-situ P-doped a:Si and in-situ P-doped polysilicon. The SiGe HBT structure including the above mentioned bilayer emitter is also described herein.

Abstract: A heterojunction bipolar transistor of the present invention is produced from a wafer including a substrate and a collector layer of a first conductivity type, a base layer of a second conductivity type and an emitter layer of the first conductivity type sequentially laminated on the substrate in this order. First, the wafer is etched up to a preselected depth of the collector layer via a first photoresist, which is formed at a preselected position on the emitter layer, serving as a mask. Subsequently, the collector layer etched with at least the sidewalls of the base layer and collector layer, which are exposed by the first etching step, and a second photoresist covering part of the surface of the collector layer contiguous with the sidewalls serving as a mask.

Abstract: A first aspect of the invention is to realize a power amplifier having high power adding efficiency and high power gain at low cost. For that purpose, in a semiconductor device using an emitter top heterojunction bipolar transistor formed above a semiconductor substrate and having a planar shape in a ring-like shape, a structure is provided in which a base electrode is present only on an inner side of a ring-like emitter-base junction region. In this way, as a result of enabling to reduce base/collector junction capacitance per unit emitter area without using a collector top structure having complicated fabricating steps, a semiconductor device having high power adding efficiency and high-power gain and suitable for a power amplifier can be realized.

Abstract: The invention is directed to semiconductor wafer structures having increased thermal conductivity over conventional semiconductor wafer designs due to the inclusion of an isotopically-enriched material on at least one surface of the wafer substrate. The isotopically-enriched material may be isotopically-enriched silicon, germanium, silicon-germanium alloys, gallium arsenide, aluminum gallium arsenide, gallium nitride, gallium phosphide, gallium indium nitride, indium phosphide or combinations and alloys of these materials. In another embodiment, the substrate is removed from the wafer structure to leave a top semiconductor layer on a layer of isotopically-enriched materials with no underlying substrate.

Abstract: A low-power bipolar transistor is formed to have a silicon germanium base region, an intrinsic emitter region with a sub-lithographic width, and an oxide layer that is self aligned to an overlying extrinsic emitter. The silicon germanium base region increases the speed of the transistor, while the small extrinsic emitter region reduces the maximum current that can flow through the transistor, and the self-aligned oxide layer and extrinsic emitter reduces the base-to-emitter junction size and device performance variability across the wafer.

Abstract: A method of manufacturing a bipolar transistor in a single-crystal silicon substrate of a first conductivity type, including a step of carbon implantation at the substrate surface followed by an anneal step, before forming, by epitaxy, the transistor base in the form of a single-crystal semiconductor multilayer including at least a lower layer, a heavily-doped median layer of the second conductivity type, and an upper layer that contacts a heavily-doped emitter of the first conductivity type.

Abstract: Disclosed is a manufacturing method to fabricate Heterojunction Bipolar Transistors (HBTs) that enables self-alignment of emitter and base metal contact layers with precise sub-micron spacing using a dielectric-assisted metal lift-off process. Such an HBT process relies on the formation of an “H-shaped” dielectric (i.e., Si3N4/SiO2) mask conformally deposited on top of the emitter contact metallization that is used to remove excess base metal through lift-off by a wet chemical HF-based etch. This HBT process also uses a thin selective etch-stop layer buried within the emitter layer to prevent wet chemical over-etching to the base and improves HBT reliability by forming a non-conducting, depleted ledge above the extrinsic base layer. The geometry of the self-aligned emitter and base metal contacts in the HBT insures conformal coverage of dielectric encapsulation films, preferably Si3N4 and/or SiO2, for reliable HBT emitter p-n junction passivation.

Abstract: A bipolar transistor device with a large current capacity is formed by connecting a plurality of transistor elements to each other in parallel, each transistor element having a collector layer, a base layer, and an emitter layer formed respectively in a semiconductor substrate. In the bipolar transistor device, the base layers of a plurality of the transistor elements are extended in parallel to each other and those base layers are separated from each other. In each separated base layer, a first base electrode is formed on a part of the base layer which is separated from an emitter junction with the emitter layer, and a second base electrode is formed on another portion of the base layer closer to the emitter junction than the first base electrode. To dispose the base electrodes of a plurality of the transistor elements in parallel to each other, a base wiring is connected to the first base electrodes of those elements electrically.

Abstract: A multiplicity of components form a photodiode array on a substrate. Each of the components consists of a transistor of the p-n-p type with the outermost p-doped layer being transformed into an optical filter by control of the anodic etching operation utilizing transistor characteristics of the respective transistor. The result can provide red, blue and green filters in a color camera.

Abstract: The present invention provides a method of manufacturing semiconductor devices, by which InGaAs-base C-top HBTs are manufactured at low cost. Helium ions with a smaller radius are implanted into a p-type InGaAs layer (in external base regions) not covered with a lamination consisting of an undoped InGaAs spacer layer, n-type InP collector layer, n-type InGaAs cap layer, and collector electrode from a direction vertical to the surface of the external base layer or within an angle of 3 degrees off the vertical. In consequence, the p-type InGaAs in the external base regions remains p-type conductive and low resistive and the n-type InAlAs layer in the external emitter regions can be made highly resistive. By this method, InGaAs-base C-top HBTs can be fabricated on a smaller chip at low cost without increase of the number of processes.