Abstract: A bipolar transistor having a base semiconductor layer structure to minimize base parasitic resistance and a method of manufacturing the bipolar transistor are provided. In the provided bipolar transistor, a collector region of a second conductivity type, which is defined by isolation regions, is formed on a semiconductor substrate of a first conductivity type. A first base semiconductor layer of the first conductivity type extends from the upper surface of the collector region to the upper surface of the isolation regions. Here, the first base semiconductor layer is formed of a silicon germanium (SiGe) layer. Second base semiconductor layers of the first conductivity type are formed on the portions of the first base semiconductor layer except for the portions having the emitter region and the emitter insulating layers. Base ohmic layers are formed on the second base semiconductor layers.

Abstract: According to one embodiment of the invention, a method for manufacturing a bipolar junction transistor includes implanting a first base dopant in a semiconductor substrate, forming an epitaxial layer outwardly from the semiconductor substrate, and forming a dielectric layer outwardly from the epitaxial layer. The method also includes etching a first portion of the dielectric layer to form an emitter region, forming an emitter polysilicon layer on the semiconductor substrate, and implanting an emitter dopant in the emitter polysilicon layer. The method further includes etching a portion of the emitter polysilicon layer and a second portion of the dielectric layer to form an emitter polysilicon region having sidewalls, forming nitride regions on the sidewalls, and implanting a second base dopant in the semiconductor substrate. After implanting the second base dopant, an annealing process is performed for the semiconductor substrate to form an emitter and a base.

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: In a method for manufacturing a semiconductor device, an N type single-crystal silicon substrate having a first silicon oxide film and a P type poly-crystal silicon layer is provided. A silicon nitride film is formed on the P type poly-crystal silicon layer. A side wall of the silicon nitride film is formed in an opening in the P type poly-crystal silicon layer above a portion expected to provide an active region. The first silicon oxide film has an opening therein which is larger than the opening formed in the P type poly-crystal silicon layer. Then, an N type IV-group semiconductor mixed crystal layer having a smaller band gap than silicon to a desired thickness is grown on the single-crystal silicon substrate on which a surface of the portion expected to provide said active region is exposed. A non-doped single-crystal silicon layer is grown on the IV-group semiconductor mixed crystal layer to a desired thickness.

Abstract: A substrate processing apparatus for forming a boron doped silicon-germanium film on one or more substrates in a reaction furnace of a low pressure CVD apparatus uses a mixture gas of GeH4 and SiH4 as a reaction gas, and BCl3 as a doping gas. The substrate processing apparatus includes a plurality of gas outlets for supplying GeH4 at different locations in the reaction tube and a doping gas line for supplying BCl3 at least at an upstream side of gas flow in the reaction tube.

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: A method of selectively forming contact regions on a substrate having a plurality of exposed regions includes selectively forming a contact region on each of the exposed regions of the substrate. During formation, each contact region has a first growth rate in a first direction and a second growth rate in a second direction. While each contact region is being selectively formed on the respective exposed region, the contact region is heated to increase the first growth rate of the contact region in the first direction relative to the second growth rate of the contact region in the second direction. The first growth rate may be a vertical growth rate and the second growth rate may be a lateral growth rate. The contact may be heated by applying electromagnetic radiation to an upper surface of the substrate and not applying the radiation to the vertical portions of the contact region to thereby increase the vertical growth rate relative to the lateral growth rate.

Abstract: Compound semiconductor structures and devices can be grown on patterned oxide layers deposited on silicon. The deposition of Group II-VI and Group II-V compound semiconductors on patterned wafers results in an increase in the critical thickness for lattice mismatched layers and the relief of strain energy through side walls. As a result, high crystalline quality compound semiconductor material can be grown on less expensive and more accessible substrate to more cost effectively produce semiconductor components and devices having enhanced reliability.

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: A method and structure for selectively growing epitaxial silicon in a trench formed within a silicon-on-insulator (SOI) structure. The SOI structure includes a buried oxide layer (BOX) on a bulk silicon substrate, and a silicon layer on the BOX. A pad layer is formed on the silicon layer. The pad layer includes a pad nitride (e.g., silicon nitride) on a pad oxide (e.g., silicon dioxide), and the pad oxide has been formed on the silicon layer. A trench is formed by anisotropically etching through the pad layer, the silicon layer, the BOX, and to a depth within the bulk silicon substrate. Insulative spacers are formed on sidewalls of the trench. An epitaxial silicon layer is grown in the trench from a bottom of the trench to above the pad layer. The pad layer and portions of the epitaxial layer are removed (e.g., by chemical mechanical polishing), resulting in a planarized top surface of the epitaxial layer that is about coplanar with a top surface of the silicon layer.

Abstract: After an amorphous semiconductor thin film is crystallized by utilizing a catalyst element, the catalyst element is removed by performing a heat treatment in an atmosphere containing a halogen element. A resulting crystalline semiconductor thin film has features that it exhibits {111} orientation and that almost all crystal lattices have continuity at a crystal boundary. This type of grain boundaries greatly contribute to improving the carrier mobility, and make it possible to realize, semiconductor devices having very high performance.

Abstract: A method of manufacturing a bipolar transistor in a P-type substrate, including the steps of forming in the substrate a first N-type area; forming by epitaxy a first silicon layer; forming in this first layer, and substantially above the first area a second heavily-doped P-type area separate from the second area; forming at the periphery of this second area a third N-type area; forming by epitaxy a second silicon layer; forming a deep trench crossing the first and second silicon layers, penetrating into the substrate and laterally separating the second area from the third area; and performing an anneal such that the dopant of the third area is in continuity with that of the first area.

Abstract: A method for fabricating bipolar transistor having insitu-formed epitaxial base is disclosed herein, the method including the following steps. The first step of the key feature according to one preferred embodiment of the present invention is to use a first epitaxial process to selectively grow an epitaxial collector layer in the etched first oxide layer. The first oxide layer is formed on a buried layer, which is formed on the silicon substrate. Then utilize a second epitaxial process to subsequently grow a first epitaxial-base layer and a second epitaxial-base layer. Particularly the second epitaxial process and the first epitaxial process are performed insitu. Then a patterned oxide layer and poly silicon layer are formed on the second epitaxial-base layer. Followed by etching the poly silicon layer and the patterned oxide layer, the second epitaxial-base layer is implanted, which together with the first epitaxial-base layer are etched.

Abstract: One embodiment is a method for fabricating the base of a bipolar transistor where the method comprises placing a first wafer in an undoped epi chamber. Next a first undoped base layer is grown over the first wafer. After growing the first undoped base layer, the first wafer is transferred from the undoped epi chamber into a separate doped epi chamber. A first doped base layer is then grown over the first undoped based layer in the doped epi chamber. While the first wafer is being processed in the doped epi chamber, a second wafer can be processed in the undoped epi chamber. Another embodiment is a structure produced by the disclosed method and yet another embodiment comprises a transfer chamber, a transfer arm, a bake chamber, and a separate undoped epi chamber and a doped epi chamber for practicing the disclosed method.

Abstract: The present invention provides a method of manufacturing a bipolar transistor. The method may comprise forming a collector in a semiconductor wafer substrate, forming a base in the collector, implanting an oxide region withing said collector and over the base, and forming an emitter over the substrate such that the oxide region is located between the emitter and the base.

Abstract: The invention relates to a process of forming a bipolar junction transistor (BJT) that includes forming a topology over a substrate. Thereafter, a spacer is formed at the topology. A base layer is formed from epitaxial silicon above the spacer and at the topology. A leakage block structure is formed in the substrate by out-diffusion from the spacer. Thereafter a BJT is completed with the base layer and the spacer.

Abstract: A method of manufacturing a semiconductor device comprising the step of epitaxially growing of an n-type doped layer of a semiconductor material using an n-type dopant gas, the growth process being performed at a pressure higher than 2.66×104 Pa.

Abstract: A heteroepitaxial structure is made using nanocrystals that are formed closer together than normal lithography patterning would allow. The nanocrystals are oxidized and thus selectively etchable with respect to the substrate and surrounding material. In one case the oxidized nanocrystals are removed to expose the substrate at those locations and selective epitaxial germanium is then grown at those exposed substrate locations. The inevitable formation of the misfit dislocations does minimal harm because they are terminated at the surrounding material. In another case the surrounding material is removed and the germanium is epitaxially grown at the exposed substrate where the surrounding material is removed. The resulting misfit dislocations in the germanium terminate at the oxidized nanocrystals.

Abstract: In order to manufacture components of a semiconductor structure, a buffer layer is epitaxially grown onto a well in a substrate. This buffer layer is subsequently removed in the region outside the wells. This measure reduces edge losses because of the conductive, autodoped layer along the boundary area of the substrate with respect to a following epitaxial layer. The components are suitable for high frequency applications.

Abstract: A method for forming an interface free layer of silicon on a substrate of monocrystalline silicon is provided. According to the method, a substrate of monocrystalline silicon having a surface substantially free of oxide is provided. A silicon layer in-situ doped is deposited on the surface of the substrate in an oxygen-free environment and at a temperature below 700° C. so as to produce a monocrystalline portion of the silicon layer adjacent to the substrate and a polycrystalline portion of the silicon layer spaced apart from the substrate. The silicon layer is heated so as to grow the monocrystalline portion of the silicon layer through a part of the polycrystalline portion of the silicon layer. Also provided is a method for manufacturing a bipolar transistor.

Abstract: A buried layer of a collector region and a buried layer of a collector taking-out region are formed at the same time at each epitaxial layer when the collector region and the collector taking-out region of the semiconductor integrated circuit device according to the invention. Each buried layer is diffused to connect, and etched in V-groove. By that, the collector region and collector taking-out region made thick in film are formed at the same time so as to realize the semiconductor integrated circuit device of high withstanding voltage.

Abstract: There is provided a method of fabricating a semiconductor device, including the steps of (a) forming a first conductivity type base region in a second conductivity type collector region by molecular beam epitaxy (MBE), (b) forming an emitter region in the base region by implanting second conductivity type impurities into the base region by MBE; (c) forming a second conductivity type amorphous layer on the emitter region by MBE, and (d) forming an emitter contact region by causing the second conductivity type amorphous layer to grow in solid phase. The method makes it possible to establish not only a base region but also an emitter region in ambient temperature growth by means of an MBE apparatus. Herein, the emitter region has a shallow depth and uniform impurities content by implanting antimony (Sb) into a region with a substrate being applied a voltage directly in an MBE apparatus.

Abstract: Chemical vapor deposition processes utilize higher order silanes and germanium precursors as chemical precursors. The processes have high deposition rates yet produce more uniform films, both compositionally and in thickness, than films prepared using conventional chemical precursors. In preferred embodiments, higher order silanes are employed to deposit SiGe-containing films that are useful in the semiconductor industry in various applications such as transistor gate electrodes.

Abstract: A method for fabricating a silicon-on-insulator (SOI) wafer that includes a monocrystalline silicon substrate with a doped region buried therein is provided. The method includes forming a plurality of trench-like openings extending from a surface of the substrate to the doped buried region, and selectively etching through the plurality of trench-like openings to change the doped buried region into a porous silicon region. The porous silicon region is oxidized to obtain an insulating region for the SOI wafer.

Abstract: A lateral bipolar transistor includes: a substrate; a first insulative region formed on the substrate; a first semiconductor region of a first conductivity type selectively formed on the first insulative region; a second insulative region formed so as to substantially cover the first semiconductor region; and a second semiconductor region of a second conductivity type different from the first conductivity type, a second semiconductor region being selectively formed, wherein: the second insulative region has a first opening which reaches a surface of the first semiconductor region, and the first semiconductor region has a second opening which reaches the underlying first insulative region, the second opening being provided in a position corresponding to the first opening of the second insulative region; the second semiconductor region is formed so as to fill the first opening and the second opening, thereby functioning as a bass region; a lower portion of the second semiconductor region which at least fills th

Abstract: There is provided a method of forming an element isolation structure that can maintain its element isolation capability even with the progress of miniaturization of semiconductor elements. Through thermal processing in a nitrogen atmosphere at 900° C., a non single-crystal silicon film (80) is crystallized into single-crystal form by epitaxial growth on the main surface of a substrate, thereby to form an epitaxial silicon film (85). The epitaxial silicon film (85) is then planarized by CMP to expose the upper surface of an element isolation insulating film (50). This completes the element isolation insulating film (50) having a two-level protruding shape.

Abstract: According to a disclosed embodiment, a base region is grown on a transistor region. A dielectric layer is next deposited over the base region. The dielectric layer can comprise, for example, silicon dioxide, silicon nitride, or a suitable low-k dielectric. Subsequently, an opening is fabricated in the dielectric layer, and an emitter layer is formed on top of the dielectric layer and in the opening. Thereafter, an anisotropic polymerizing etch chemistry is utilized to etch the emitter layer down to a first depth, forming an emitter region in the opening. Next, a non-polymerizing etch chemistry having isotropic components is used to create a notch in the dielectric layer below the emitter region. The formation of the notch reduces the overlap area of a capacitor that forms between the emitter region and the base region, which translates to a lower level of emitter to base capacitance.

Abstract: A semiconductor device includes a semiconductor substrate, an insulating film having one portion below a surface of the semiconductor substrate and the other portion on the semiconductor substrate in a second region to the same thickness as the insulating film, which improves an operation speed even at a low voltage.

Abstract: A bipolar transistor according to the invention is provided with structure that an intrinsic base made of single crystal Si—Ge and a base leading-out electrode are connected via a link base made of polycrystal Si—Ge by doping at high concentration, further, a part immediately under the intrinsic base has the same conductive type as that of a collector and in a peripheral part, a single crystal Si—Ge layer having the same conductive type as that of a base is provided between the intrinsic base and a collector layer. Hereby, the reduction of the resistance of the link base between the intrinsic base and the base leading-out electrode and the reduction of capacitance between the collector and the base are simultaneously realized, and a self-aligned bipolar transistor wherein capacitance between an emitter and the base and capacitance between the collector and the base are respectively small, power consumption is small and high speed operation is enabled is acquired.

Abstract: A method for fabricating a bipolar device, including the steps of forming an epitaxial growth retarding layer on a substrate at a predetermined angle, forming a collector layer on the substrate so that the collector layer is adjacent the epitaxial growth retarding layer and has an inclined portion formed over an edge portion of the epitaxial growth retarding layer, forming a base layer having an inclined portion on the collector layer, and forming an emitter layer on the inclined portion of the base layer.

Abstract: A method of forming a semiconductor device with a SEG layer and isolating elements formed in the device includes forming an insulating layer for isolating elements on a silicon substrate. An open area is formed in the insulating layer to expose the surface of the silicon substrate by selectively etching the insulating layer. The open area in the insulating layer includes an inclined side wall at a positive angle of inclination. An epitaxial layer is selectively grown to have a top surface lower than the surface of the insulating layer, using the silicon exposed in the open area as a seed. A sacrificial oxide layer is formed on the surface of the silicon of the epitaxial growth, and the sacrificial oxide layer is then removed.

Abstract: Bipolar transistors of different designs, particularly designs optimized for different high frequency applications are formed on the same substrate by separate base layer formation processes for epitaxial growth including different material concentration profiles of germanium, boron and/or carbon. Epitaxial growth of individual growth layers by low temperature processes is facilitated by avoiding etching of the silicon substrate including respective collector regions through use of an etch stop that can be etched selectively to silicon. Annealing processes can be performed between growth of respective base layers and/or performed collectively after all transistors are substantially completed.

Abstract: This invention relates to a bi-polar transistor and a procedure for its manufacture. The task of the invention is to propose a bi-polar transistor and a procedure for its manufacture that eliminates the disadvantages of conventional arrangements for a simple polysilicon technology with differential epitaxy for the manufacture of the base, in order to further improve especially the high-speed properties of a bi-polar transistor, to produce highly conductive connections between the metal contacts and the active (inner) transistor region as well as a minimized passive transistor surface, and to simultaneously avoid any additional process complexity and increased contact resistance. This invention resolves the task in that, by creating suitable epitaxy process conditions, the polysilicon layer is deposited on the insulator zone with a greater thickness than the epitaxy layer in the active transistor zone.

Abstract: A method of forming a notched gate structure having substantially vertical sidewalls and a sub-0.05 &mgr;m electrical critical dimension is provided. The method includes forming a conductive layer on an insulating layer; forming a mask on the conductive layer so as to at least protect a portion of the conductive layer; anisotropically etching the conductive layer not protected by the mask so as to thin the conductive layer to a predetermined thickness and to form a conductive feature underlying the mask, the conductive feature having substantially vertical sidewalls; forming a passivating layer at least on the substantially vertical sidewalls; and isotropically etching remaining conductive layer not protected by the mask to remove the predetermined thickness thereby exposing a lower portion of said conductive feature not containing the passivating layer, while simultaneously removing notched regions in the lower portion of the conductive feature.

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

Abstract: In accordance with the invention, a bipolar transistor is fabricated by disposing a sacrificial layer over the conventional semiconductor workpiece. The sacrificial layer is patterned into a stripe corresponding to the emitter stripe, and the base contacts are formed in relation to the sacrificial stripe. The stripe is removed, and the base and emitter are formed. In the preferred embodiment, the sacrificial layer is a stack of layers providing etch selectivity.

Abstract: A method of fabricating an integrated circuit insulator stack, such as an emitter window dielectric, is disclosed. A single vacuum sequence (50) is performed in a low pressure chemical vapor deposition (LPCVD) process chamber. In one disclosed example, a layer of silicon dioxide (20) is first deposited by the chemical vapor deposition (44) of bistertiarybutylaminosilane (BTBAS) in the presence of oxygen; before removing the wafer from the process chamber, a layer of silicon nitride (22) is then deposited by the chemical vapor deposition (48) of BTBAS in ammonia. The CVD processes (44, 48) are performed at low pressures, such as 500 mTorr or less, and at low temperatures, such as below 650° C.

Abstract: A semiconductor device includes a semiconductor substrate, an insulating film having one portion below a surface of the semiconductor substrate and the other portion above the surface of the semiconductor substrate a first region, and a semiconductor layer formed on the semiconductor substrate in a second region to the same thickness as the insulating film, which improves an operation speed even at a low voltage.

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: A process for fabricating a bipolar junction transistor, featuring the use of multiple self-aligned collector regions, used to limit the width of the base region of the transistor, has been developed. The self-aligned collector regions are formed via multiple ion implantation procedures, performed through, and self-aligned to, an overlying emitter opening, in an oxide layer. The self-aligned collector regions, completely fill the space in the lighter doped collector region, located between the overlying base region, and the underlying subcollector region.

Abstract: In a method of manufacturing a semiconductor device, a first insulating film is formed on a semiconductor substrate, a first conductive film is formed on the first insulating film, and a second insulating film is formed on the first conductive film. An opening is formed to the semiconductor substrate through the second insulting film, the first conductive film and the first insulting film to expose a portion of a surface of the semiconductor substrate and a portion of a surface of the first conductive film. The exposed surface portion of the first conductive film is covered by a covering film. Thermal treatment is carried out to clean the exposed surface portion of the semiconductor substrate. A spacer film is formed in the opening on the exposed surface portion of the semiconductor substrate, and then the covering film is removed. Subsequently, an electrode film is formed on the spacer film.

Abstract: A method for fabricating bipolar transistor frequently used in high frequency circuit is disclosed herein. The foregoing method includes the following steps. First, a first oxide layer is formed on a p-type substrate, followed by developing a first photoresist pattern on the first oxide layer. A first, doped region is formed in the exposed substrate by a first implanting step. The first doped region comprises a n+ buried layer. Stripping of the first photoresist pattern, and annealing of the n+ buried layer follow. Removal of the first oxide layer to expose the n+ buried layer and a portion of the p-type substrate follows thereafter. These steps are followed by growing a first epitaxial layer on the n+ buried layer and a portion of the substrate, then a second epitaxial layer is formed on the first epitaxial layer. The first epitaxial layer is made of epitaxial n-type silicon, and the second epitaxial layer is made of in situ epitaxial p-type SiGe.

Abstract: The manufacturing of a bipolar transistor, including the steps of depositing a P-type polysilicon layer and an insulating layer on an N-type substrate; defining in said layers a base-emitter opening; performing a P-type doping and annealing to form a heavily-doped region partially extending under the periphery of the polysilicon layer; forming a spacer in an insulating material inside the opening; isotropically etching the silicon across a thickness greater than that of the heavily-doped region to form a recess; conformally forming by selective epitaxy a P-type silicon layer to form the transistor base layer; and depositing N-type heavily-doped polysilicon to form the transistor emitter.

Abstract: In accordance with the above first embodiment of the present invention, after a base polysilicon film has been grown, a lump anneal is carried out because of an extremely small variation to the silicon dioxide film. Subsequently, a buffered fluorine acid is used which has a large selective etching ratio of the silicon oxide film to the polysilicon film to side-etch the silicon oxide film in the horizontal direction by a predetermined width before the base impurity BF2+ is implanted and then the emitter polysilicon film is formed. For those reasons, a variation in distance between the n+-substrate and a collector is small. The base width “WB” of the base region is not varied, whereby variations in high frequency performance of the bipolar transistor are suppressed.

Abstract: A bipolar transistor is described whose I-V curve is such that it operates in two regions, one having low gain and low power consumption and another having higher gain and better current driving ability. Said transistor has a base region made up of two sub regions, the region closest to the emitter having a resistivity about an order a magnitude lower than the second region (which interfaces with the collector). A key feature of the invention is that the region closest to the collector is very uniformly doped, i.e. there is no gradient or built-in field present. In order to produce such a region, epitaxial growth along with boron doping is used rather than more conventional techniques such as ion implantation and/or diffusion.

Abstract: A manufacturing method of a bipolar transistor that can reduce, without increasing capacitance between base-collector, withstand voltage deterioration and leakage between emitter-base is provided. On an upper surface of an active area of a semiconductor substrate on which an isolation structure is formed by a first insulating film, a first epitaxial growth layer is formed. Then, on an upper surface of a first epitaxial growth layer a third insulating layer is formed in an area larger than that of the first epitaxial growth layer. Thereafter, from a side surface of a first epitaxial growth layer, a second epitaxial growth layer is formed in an area larger than that of a third insulating layer. Thereafter, all over the surface of the semiconductor substrate a first poly-silicon layer, a fourth and fifth insulating layers are formed, an opening is opened with an area approximately equal with that of an active area, and inside the opening a second poly-silicon layer and emitter layer are formed.

Abstract: A method for fabricating a buried layer pinched collector bipolar, (BPCB), device, sharing several process steps with simultaneously formed CMOS devices, has been developed. The BPCB device fabrication sequence features the use of polysilicon field plates,. placed on field oxide regions, in an area of an N well region in which the field oxide regions are located between subsequent P type, base and N type, collector regions. The use of the polysilicon field plates results in an increase in collector—emitter breakdown voltage, as a result of a reduction in the electric field at the surface underlying the polysilicon field plates.

Abstract: Base layer formation without the use of selective epitaxial deposition is described. The process begins with the deposition of a seed layer of polysilicon over both the field oxide and the wafer surface that lies between them. An opening in said seed layer is then formed, between the areas of field oxide (and overlying an N+ buried layer). Non-selective epitaxial growth is then used to deposit the transistor's base layer. This automatically results in the formation of self aligned butted contacts of polysilicon on either side of the base. Manufacture of the transistor is completed in the usual way—emitter formation, emitter poly contact formation, ILD deposition, etc.

Abstract: A method of fabricating a self-aligned bipolar junction transistor in a semiconductor structure having a first layer of silicon carbide generally having a first conductivity type and a second layer of silicon carbide generally having a second conductivity type, opposite to the first conductivity type. The method comprises forming a pillar in the second silicon carbide layer, the pillar having a side wall and defining an adjacent horizontal surface on the second layer, forming a dielectric layer having a predetermined thickness on the second semiconductor layer, including the side wall and the horizontal surface. After formation of the dielectric layer, the dielectric layer on a portion of the horizontal surface adjacent the side wall is anisotropically etched while at least a portion of the dielectric layer remains on the side wall, thereby exposing a portion of the horizontal surface.

Abstract: A bipolar transistor has a lightly doped n-type single crystal silicon layer epitaxially grown in a recess formed in a heavily doped n-type impurity region after a selective growth of a thick field oxide layer, a base region, an emitter region and a collector contact region are formed in surface portions of the lightly doped n-type single crystal silicon layer, and the single crystal silicon layer is not affected by the heat during the growth of the thick field oxide layer, and has a flat zone constant in dopant concentration regardless of the thickness thereof.