Abstract: Si and SiGeC layers are formed in an NMOS transistor on a Si substrate. A carrier accumulation layer is formed with the use of a discontinuous portion of a conduction band present at the heterointerface between the SiGeC and Si layers. Electrons travel in this carrier accumulation layer serving as a channel. In the SiGeC layer, the electron mobility is greater than in silicon, thus increasing the NMOS transistor in operational speed. In a PMOS transistor, a channel in which positive holes travel, is formed with the use of a discontinuous portion of a valence band at the interface between the SiGe and Si layers. In the SiGe layer, too, the positive hole mobility is greater than in the Si layer, thus increasing the PMOS transistor in operational speed. There can be provided a semiconductor device having field-effect transistors having channels lessened in crystal defect.

Abstract: A GaN-based semiconductor device made of GaN-based semiconductor materials includes a bank made of a first undoped material and formed on a base layer, a thin layer made of a second undoped material having higher band-gap energy than the first undoped material and formed on a side wall surface of the bank, the thin layer having a heterojunction with the first undoped material, a source electrode formed on the bank so as to extend beyond the heterojunction between the bank and the thin layer, and a drain electrode formed on the reverse surface of the base layer, wherein a two-dimensional electron gas layer is formed between the source and drain electrodes in parallel with the heterojunction.

Abstract: A SiGe bipolar transistor including a semiconductor substrate having a collector and sub-collector region formed therein, wherein the collector and sub-collector are formed between isolation regions that are also present in the substrate is provided. Each isolation region includes a recessed surface and a non-recessed surface which are formed utilizing lithography and etching. A SiGe layer is formed on the substrate as well as the recessed non-recessed surfaces of each isolation region, the SiGe layer includes polycrystalline Si regions and a SiGe base region. A patterned insulator layer is formed on the SiGe base region; and an emitter is formed on the patterned insulator layer and in contact with the SiGe base region through an emitter window opening.

Abstract: An improved HBT of the invention reduces the current blocking effect at the base-collector interface. Nitrogen is incorporated at the base-collector interface in an amount sufficient to reduce the conduction band energy of the collector at the base-collector interface to equal the conduction band energy of the base. In a preferred embodiment, a nitrogen concentration on the order of 2% is used in a thin ˜20 nm layer at the base-collector interface. Preferred embodiment HBTs of the invention include both GaAs HBTs and InP transistors in various layer structures, e.g., single and double heterojunction bipolar transistors and blocked hole bipolar transistors.

Abstract: A bipolar transistor having base and collector regions of narrow bandgap semiconductor material and a minority-carrier excluding base contact has a base doping level greater than 1017 cm−3. The transistor has a greater dynamic range, greater AC voltage and power gain-bandwidth products and a lower base access resistance than prior art narrow band-gap bipolar transistors.

Abstract: In accordance with the present invention, the gate length and the gate insulation film thickness are different between the p-channel MOS field effect transistors serving as the driver gates and the n-channel MOS field effect transistors forming the flip flop. Namely, the p-channel MOS field effect transistors serving as the driver gates have a larger gate length and a smaller gate oxide film thickness than the n-channel MOS field effect transistors forming the flip flop.

Abstract: A display device includes pixels disposed in a matrix on a transparent base plate. Each pixel includes an opening region, in which an electro-optic element for emitting light through the base plate is formed, and a non-opening region, in which a thin film transistor for driving the electro-optic element is formed. The non-opening region has a first film structure including the thin film transistor. The opening region has a second film structure extending from the first film structure and existing between the electro-optic element and the base plate. The second film structure is different from the first film structure so as to adjust the light passing through the opening region.

Abstract: A normally “off” enhancement mode junction field effect transistor (JFET) is disclose. The JFET has a low threshold voltage in the range of 0.2 to 0.3 volts and a low on resistance. The Drain-to-Source voltage drop is less than 0.1 volt at a drain current of 100 amperes.

Abstract: A semiconductor device includes first and second polysilicon areas on a chip. The first polysilicon area corresponds to circuit elements of the semiconductor device. At least some of the first polysilicon corresponds to polysilicon gates. At least some of the second polysilicon area comprises contacts of the semiconductor device. Metal covers the polysilicon contacts.

Abstract: An object of the invention is to decrease leakage current of a nonvolatile memory and to design improvement of memory characteristic thereof. The invention is characterized by comprising an FET of MFMIS structure having metal layer (M) and insulation layer (I) on boundary of a ferroelectrics and a semiconductor as a buffer layer, and further by letting an insulation barrier layer between a floating gate or a control gate and a ferroelectric layer.

Abstract: A single transistor (“1T”) ferroelectric memory cell, device and method for the formation of the same incorporating a high temperature ferroelectric gate dielectric. The memory cell of the present invention comprises a substrate, an overlying ferroelectric layer, which may comprise a film of rare earth manganite, and an interfacial oxide layer intermediate the substrate and the ferroelectric layer. In a preferred embodiment, the ferroelectric material utilized in an implementation of the present invention may be deposited by metallorganic chemical vapor deposition (“MOCVD”) or other techniques and exhibits a low relative dielectric permittivity of around 10 and forms an interfacial layer with a relative dielectric permittivity larger than that of SiO2, which makes it particularly suitable for a 1T cell.

Abstract: An etch stopper member is formed under a cell plate electrode so as to surround an active region along a periphery of the cell plate electrode. The etch stopper member is formed from a material that is resistant to an etchant of a first interlayer insulating film. For example, a dummy gate line and a cylindrical wall formed thereon are provided as the etch stopper member. Either the dummy gate line or the cylindrical wall may be provided as the etch stopper member. The etch stopper member prevents the interlayer insulating film from being laterally etched at the boundary between a DRAM memory section and a logic section. This eliminates the need to provide an etching margin, allowing for reduction in the area of the DRAM memory section.

Abstract: A semiconductor integrated circuit device has a semiconductor substrate and operates when supplied with appositive supply voltage and a circuit ground potential. The device has word lines, pairs of bit lines, data storage capacitors, and N-channel MOSFETs each having a gate connected to any one of the word lines and a source-drain path interposed between one of the paired bit lines on the one hand and a terminal of any one of the data storage capacitors on the other hand. A positive internal voltage higher than a circuit ground potential is generated and fed as a bias voltage to P-type regions wherein address selection MOSFETs of dynamic memory cells are formed.

Abstract: A trench capacitor has a first capacitor electrode, a second capacitor electrode, and a dielectric, which is arranged between the capacitor electrodes. The first capacitor electrode has a tube-like structure, which extends into a substrate. The second capacitor electrode includes a first section which is opposite to the internal side of the tube-like structure, with the dielectric arranged therebetween, and a second section, which is opposite to the external side of the tube-like structure with the dielectric arranged therebetween.

Abstract: In a semiconductor device having P type and N type wells formed bordering on a step on a P type semiconductor substrate, a first transistor (precise transistor) having a first linewidth is formed on the P type well in a step lower region while a second transistor (high-voltage transistor) having a second linewidth greater than a linewidth of the first transistor is formed on the N type well in a step higher region.

Abstract: A phase-change memory may be formed with at least two phase-change material layers separated by a barrier layer. The use of more than one phase-change layer enables a reduction in the programming volume while still providing adequate thermal insulation.

Abstract: A voltage-variable capacitor uses the channel-to-substrate junction from a gated diode formed from a metal-oxide-semiconductor transistor. The transistor gate has at least two contacts that are biased to different voltages. The gate acts as a resistor with current flowing from an upper gate contact to a lower gate contact. The gate-to-source voltage varies as a function of the position. A critical voltage is where the gate-to-source voltage is equal to the transistor threshold. A portion of the gate that has gate voltages above the critical voltage has an inversion layer or conducting channel under the gate. Another portion of the gate has gate voltages below the critical voltage, and thus no channel forms. By varying either the gate voltages or the source voltage, the area of the gate that has a channel under it is varied, varying the channel-to-substrate capacitance. Separate gate arms reduce bias current.

Abstract: A field-effect semiconductor element implemented with a fewer number of elements and a reduced area and capable of storing data by itself without need for cooling at a cryogenic temperature, and a memory device employing the same. Gate-channel capacitance is set so small that whether or not a trap captures one electron or hole can definitely and distinctively be detected in terms of changes of a current of the semiconductor FET element. By detecting a change in a threshold voltage of the semiconductor element brought about by trapping of electron or hole in the trap, data storage can be realized at a room temperature.

Abstract: A PIP (Poly-Interpoly-Poly) capacitor with high capacitance is provided in a split-gate flash memory cell. A method is also disclosed to form the same PIP capacitor where the bottom and top plates of the capacitor are formed simultaneously with the floating gate and control gate, respectively, of the split-gate flash memory cell. Furthermore, the thin interpoly oxide of the cell, rather than the thick poly-oxide over the floating gate is used as the insulator between the plates of the capacitor. The resulting capacitor yields high storage capacity through high capacitance per unit area.

Abstract: A non-volatile semiconductor memory device includes a p-type Si substrate, an n-type well formed in the Si substrate, a control gate of a p-type buried diffusion region formed in the n-type well, an active region formed in the Si substrate in the vicinity of the n-type well and covered by a tunneling insulation film, and a floating gate electrode formed on the Si substrate so as to achieve a capacitance coupling with the p-type buried diffusion region, wherein the floating gate electrode extends on the active region over the tunneling insulation film, and the active region including a pair of n-type diffusion regions are formed at both sides of the floating gate electrode as source and drain regions, the n-type diffusion region forming the source region having an n−-type diffusion region at the side facing the n-type diffusion region forming said drain region.

Abstract: A MONOS memory transistor capable of high speed write with a small current and superior in scaling, comprised of substrate (well W), a channel forming region, a first and a second impurity regions SBLi, SBLi+1 comprised of an opposite conductivity type semiconductor and sandwiching the channel forming region between them and acting as a source and a drain in operation, gate insulating films 10a, 10b, 14 and gate electrode WL on the channel forming region, and a charge storing means (carrier trap) which is formed in the gate insulating films 10a and 10b and dispersed in the plane facing the channel forming region and in the direction of thickness and is injected with hot holes caused by a band-to-band tunnel current from the impurity regions SLi or SLi+1 in operation.

Abstract: A method and/or system and/or apparatus for a molecular-based FET device (an m-FET) uses charge storing molecules between a gate and channel of an FET-type transistor. Further embodiments describe fabrication methods for using combinations of standard practices in lithography and synthetic chemistry and novel elements.

Abstract: A multi-storage nonvolatile memory of high density, high speed and high reliability has a memory transistor and switch transistors disposed on both the sides of the memory transistor. The memory transistor includes a gate insulating film having discrete traps and a memory gate electrode, whereas the switch transistors include switch gate electrodes. The gate insulating film has the discrete traps for storing information charge, can locally inject carriers, and one memory cell constitutes a multi-storage cell for storing at least information of 2 bits. The switch transistors having the switch gate electrodes realize source side injection. The memory transistor is fommed together with the switch transistors in self-aligned diffusion. The memory gate electrode of the memory transistor is connected to a word line so as to perform word-line erase.

Abstract: A MOS control diode is provided for power switching. In the MOS control diode, a switching speed is high and a reverse leakage current characteristic is improved without additionally needing processes for improving reverse recovery time by converting a power MOSFET which is a majority carrier device to diode having two terminals. Such a MOS control diode can be achieved by forming a discontinuous area in a gate oxide film formed on the surface of a semiconductor substrate so that the conductive gate electrode is connected to the semiconductor substrate. Also, it is possible to form a trench in the semiconductor substrate, to form the gate oxide films on the sidewall of a trench, and to connect the gate electrode to the semiconductor substrate through the bottom of the trench.

Abstract: A trench MOSFET device comprising: (a) a silicon substrate of a first conductivity type (preferably N-type conductivity); (b) a silicon epitaxial layer of the first conductivity type over the substrate, the epitaxial layer having a lower majority carrier concentration than the substrate; (c) a body region of a second conductivity type (preferably P-type conductivity) within an upper portion of the epitaxial layer; (d) a trench having trench sidewalls and a trench bottom, which extends into the epitaxial layer from an upper surface of the epitaxial layer and through the body region of the device; (f) an oxide region lining the trench, which comprises a lower segment covering at least the trench bottom and upper segments covering at least upper regions of the trench sidewalls; (g) a conductive region within the trench adjacent the oxide region; and (h) a source region of the first conductivity type within an upper portion of the body region and adjacent the trench.

Abstract: A semiconductor power component is described having a rear-side anode contact, a rear-side emitter region of a first conductivity type, which is connected to the rear-side anode contact, a drift region, which is connected to the rear-side emitter region and partially extends to the front-side surface, a front-side MOS control structure, and a front-side cathode contact, which is connected to the source region and the body region. The drift region includes a first drift region of the second conductivity type, a second drift region of the second conductivity type, and a third drift region of the first conductivity type. The first drift region is a buried region. The second drift region connects the front-side surface to the first drift region. The third drift region borders on a body region and connects the front side surface to the first drift region.

Abstract: A semiconductor device facilitates obtaining a higher breakdown voltage in the portion of the semiconductor chip around the drain drift region and improving the avalanche withstanding capability thereof. A vertical MOSFET according to the invention includes a drain layer; a drain drift region on drain layer, drain drift region including a first alternating conductivity type layer; a breakdown withstanding region (the peripheral region of the semiconductor chip) on drain layer and around drain drift region, breakdown withstanding region providing substantially no current path in the ON-state of the MOSFET, breakdown withstanding region being depleted in the OFF-state of the MOSFET, breakdown withstanding region including a second alternating conductivity type layer, and an under region below a gate pad, and the under region including a third alternating conductivity type layer.

Abstract: A semiconductor integrated circuit includes: a logic circuit section including transistors formed on an SOI substrate; and a partially-depletion-type transistor, which is formed on the SOI substrate as a switching transistor for controlling ON/OFF states of the logic circuit section and which has a body contact portion. The partially-depletion-type transistor has a threshold voltage, which is substantially equal to that of the transistors in the logic circuit section when no potential is applied to the body contact portion and which is higher than that of the transistors in the logic circuit section when a potential is applied to the body contact portion.

Abstract: A semiconductor-on-insulator (SOI) device includes a thermoelectric cooler on a back side of the device. The thermoelectric cooler is formed on a thinned portion of a deep bulk semiconductor layer of the SOI device. The thermoelectric device includes a plurality of pairs of opposite conductivity semiconductor material blocks formed on a metal layer deposited on the thinned portion. The thinning of the thinned portion may be accomplished in multiple etching steps of the deep silicon layer, such as a fast etching down to an etch stop and a slower, more controlled etch to the desired thickness for the thinned portion.

Abstract: An ESD diode protects a circuit against electrostatic discharge (ESD). The ESD diode has four adjacent regions. The first and third regions are formed by doping a semiconductor substrate so that it has a P-type conductivity. The second and fourth regions are formed by doping the semiconductor substrate so that it has an N-type conductivity. The first region is for connection to a signal terminal of the circuit being protected when the fourth region is connected to a positive power line of the circuit. The fourth region is for connection to the signal terminal when the first region is connected to the ground line or a negative power line of the circuit.

Abstract: A new type of partially-depleted SOI MOSFET is described in which a tunneling connection between the gate and the base is introduced. This is achieved by using a gate dielectric whose thickness is below its tunneling threshold. The gate pedestal is made somewhat longer than normal and a region near one end is implanted to be P+ (or N+ in a PMOS device). This allows holes (electrons for PMOS) to tunnel from gate to base. Since the hole current is self limiting, applied voltages greater than 0.7 volts may be used without incurring excessive leakage (as is the case with prior art DTMOS devices). A process for manufacturing the device is also described.

Abstract: In a SiC substrate (10), a first active region (12) composed of n-type heavily doped layers (12a) and undoped layers (12b), which are alternately stacked, and a second active region (13) composed of p-type heavily doped layers (13a) and undoped layers (13b), which are alternately stacked, are provided upwardly in this order. A Schottky diode (20) and a pMOSFET (30) are provided on the first active region (12). An nMOSFET (40), a capacitor (50), and an inductor (60) are provided on the second active region (13). The Schottky diode (20) and the MOSFETs (30, 40) have a breakdown voltage characteristic and a carrier flow characteristic due to a multilayer structure composed of &dgr;-doped layers and undoped layers and are integrated in a common substrate.

Abstract: A memory cell, which is isolated from other memory cells by STI trenches, each includes an ONO layer structure between a gate electrode and a channel region formed in a semiconductor body. The gate electrode is a component of a strip-shaped word line. Source and drain regions are disposed between gate electrodes of adjacent memory cells. Source regions are provided with polysilicon layers, in the form of a strip, as common source lines. Drain regions are connected as bit lines through polysilicon fillings to metallic interconnects applied to the top face of the semiconductor body.

Abstract: The present invention provides a twin bit cell flash memory device and its fabricating method. The method is to first form a gate oxide layer on the surface of the silicon substrate followed by forming a polysilicon germanium (Si1−xGex, x=0.05˜1.0) layer on the gate oxide layer. Thereafter, an ion implantation process is performed to form at least one insulating region in the polysilicon germanium layer for separating the polysilicon germanium layer into two isolated conductive regions and forming a twin bit cell structure. Then, a dielectric layer is formed on the polysilicon germanium layer and a photo-etching-process (PEP) is performed to etch portions of the dielectric layer and the polysilicon germanium layer for forming a floating gate of the twin bit cell flash memory. Finally, a control gate is formed over the floating gate.

Abstract: The present invention provides an integrated circuit which comprises a substrate having a plurality of device regions formed therein, said plurality of device regions being electrically isolated from each other by shallow trench isolation (STI) regions and said plurality of device regions each having opposing edges abutting its corresponding STI region; selected ones of said devices regions having a preselected first device width such that an oxide layer formed thereon includes substantially thicker perimeter regions, along said opposing edges, compared to a thinner central region that does not abut its corresponding STI region; and selected other ones of the device regions having a preselected device width substantially narrower in width than the first device width such that an oxide layer formed thereon includes perimeter regions, along opposing edges, that abut each other over its central region thereby preventing formation of a corresponding thinner central region.

Abstract: A semiconductor structure an a process for its manufacture. First and second gate dielectric layers are formed on a semiconductor substrate between nitride spacers, and a metal gate electrode is formed on the gate dielectric layers. Lightly-doped drain regions and source/drain regions are disposed in the substrate and aligned with the electrode and spacers. A silicide contact layer is disposed over an epitaxial layer on the substrate over the source/drain regions. The metal gate electrode is aligned using a polysilicon alignment structure, which permits high temperature processing before the metal is deposited.

Abstract: In a manufacturing method of an active matrix type liquid crystal display device, a semiconductor device having good TFT characteristics is realized. LDD regions of a driver circuit NTFT and LDD regions of a pixel section NTFT are given different impurity concentration. An impurity is doped at differing concentrations using a mask. Thus a liquid crystal display device provided with a driver circuit having high speed operation and a pixel section with high reliability can be obtained.

Abstract: A semiconductor device is disclosed that can include a gate electrode (6) having a lower layer (6a) and a higher layer (6b), a mask insulating film (7) formed over a higher layer (6b). A side surface insulating film (9) may be formed on sides of a gate electrode (6) and a side wall insulating film (8) may be formed on the sides of a gate electrode (6) and mask insulating film (7). A low density impurity region (3) may be formed with a gate electrode (6) and side surface insulating film (9) as a mask. A higher density impurity region (4) may be formed with a gate electrode (6) and side wall insulating film (8) as a mask. A contact plug (10) may be formed between side wall insulating films (8) that contacts a higher density impurity region (4). A gate electrode (6) may have a reverse tapered shape when viewed in cross section. A lower layer (6a) may have a reverse tapered shape and/or a side surface insulating film (9) may have a greater thickness on sides of a higher layer (6b) than on a lower layer (6a).

Abstract: A process for fabrication of a semiconductor device including a modified ONO structure, including forming the modified ONO structure by providing a semiconductor substrate; forming a first oxide layer on the semiconductor substrate; depositing a layer comprising a high-K dielectric material on the first oxide layer; and forming a top oxide layer on the layer comprising a high-K dielectric material. The semiconductor device may be, e.g., a MIRRORBIT™ two-bit EEPROM device or a floating gate flash device including a modified ONO structure.

Abstract: A field effect transistor has an inverse-T gate conductor having a thicker center portion and thinner wings. The wings may be of a different material different than the center portion. In addition, gate dielectric may be thicker along edges than in the center. Doping can also be different under the wings than along the center portion or beyond the gate. Regions under the wings may be doped differently than the gate conductor. With a substantially vertical implant, a region of the channel overlapped by an edge of the gate is implanted without implanting a center portion of the channel, and this region is blocked from receiving at least a portion of the received by thick portions of the gate electrode.

Abstract: This invention discloses a process for forming durable anti-stiction surfaces on micromachined structures while they are still in wafer form (i.e., before they are separated into discrete devices for assembly into packages). This process involves the vapor deposition of a material to create a low stiction surface. It also discloses chemicals which are effective in imparting an anti-stiction property to the chip. These include polyphenylsiloxanes, silanol terminated phenylsiloxanes and similar materials.

Abstract: A three axis MEM tunneling/capacitive sensor and method of making same. Cantilevered beam structures for at least two orthogonally arranged sensors and associated mating structures are defined on a first substrate or wafer, the at least two orthogonally arranged sensors having orthogonal directions of sensor sensitivity. A resonator structure of at least a third sensor is also defined, the third sensor being sensitive in a third direction orthogonal to the orthogonal directions of sensor sensitivity of the two orthogonally arranged sensors and the resonator structure having a mating structure thereon. Contact structures for at least two orthogonally arranged sensors are formed together with mating structures on a second substrate or wafer, the mating structures on the second substrate or wafer being of a complementary shape to the mating structures on the first substrate or wafer.

Abstract: There is provided, according to one embodiment of this invention, a semiconductor memory device comprising first memory elements to store a first state or a second state according to a change in resistance value, each of the first memory elements comprising one terminal and the other terminal, the first memory elements arranged parallel with each other, a first wiring connected with the one terminal of each of the first memory elements, and a second wiring formed in parallel with the first wiring and connected with the other terminal of each of the first memory elements, wherein the first state or the second state stored in one of selected from the first memory elements is read out by delivering an electric current from one of the first and second wirings via the one of selected from the first memory elements to the other of the first and second wirings.

Abstract: A hermetically sealing package for an optical semiconductor equipped with a light transmitting window whose light transmitting surface is inclined at least six degrees from the vertical line of the package bottom plate and which is joined to a cylindrical component on the package side wall by the use of a solder brazing material, in which the window material is made of a light-transmitting ceramic (such as alumina or spinel) plate in a substantially regular hexagonal or disk form in which a metallized portion is formed around the periphery, leaving a circular light transmitting portion in the center of the plate; and an optical semiconductor module that makes use of the package. The hermetically sealing package and the optical semiconductor module are easy and inexpensive to manufacture, have high reliability, and do not deform the plane of polarization.

Abstract: Isolation of a heterojunction bipolar transistor device in an integrated circuit is accomplished by forming the device within a trench in dielectric material overlying single crystal silicon. Precise control over the thickness of the initially-formed dielectric material ultimately determines the depth of the trench and hence the degree of isolation provided by the surrounding dielectric material. The shape and facility of etching of the trench may be determined through the use of etch-stop layers and unmasked photoresist regions of differing widths. Once the trench in the dielectric material is formed, the trench is filled with selectively and/or nonselectively grown epitaxial silicon. The process avoids complex and defect-prone deep trench masking, deep trench silicon etching, deep trench liner formation, and dielectric reflow steps associated with conventional processes.

Abstract: A method of forming FLASH memory circuitry having an array of memory cells and having FLASH memory peripheral circuitry operatively configured to at least read from the memory cells of the array, includes forming a plurality of spaced isolation trenches within a semiconductor substrate within a FLASH memory array area and within a FLASH, peripheral circuitry area peripheral to the memory array area. The forming includes forming at least some of the isolation trenches within the FLASH memory array to have maximum depths which are different within the substrate than that of at least some of the isolation trenches within the FLASH peripheral circuitry area.

Abstract: An apparatus including a contact point on a substrate; a first dielectric layer comprising a material having a dielectric constant less than five formed on the contact point, and a different second dielectric layer formed on the substrate and separated from the contact point by the first dielectric layer. Collectively, the first and second dielectric layers comprise a composite dielectric layer having a composite dielectric constant value. The contribution of the first dielectric layer to the composite dielectric value is up to 20 percent. Also, a method including depositing a composite dielectric layer over a contact point on a substrate, the composite dielectric layer comprising a first material having a dielectric constant less than 5 and a second different second material, and forming a conductive interconnection through the composite dielectric layer to the contact point.

Abstract: Formed on the surface of an n-type semiconductor layer (21) taken as a collector region is a base region (22) consisting of a p-type region, and formed in the p-type region is an emitter region (23) consisting of an n+-type region. Further, provided in the base region is a base electrode connecting portion (24) consisting of an n+-type region, and a base electrode (26) is connected to the surface of the base electrode connecting portion, and an emitter electrode (27) and a collector electrode (28) are provided and connected electrically to the emitter region and the collector region (21), respectively. As a result, a semiconductor device is obtained which has the transistor in which the reduction in power consumption with a high withstand voltage can be achieved, and the fast switching speed is possible and the large current is obtained. Further a voltage-drive type bipolar transistor such as a digital transistor is obtained which is small in load capacity while establishing a desired drive voltage.

Abstract: A method for adjusting the gain or the sensitivity of a lateral component formed in the front surface of a semiconductor wafer, having a first conductivity type, includes not doping or overdoping, according to the first conductivity type, the back surface when it is desired to reduce the gain or sensitivity of the lateral component, and doping according to the second conductivity type, the back surface, when the gain or the sensitivity of the lateral component is to be increased.

Abstract: A Si1-xGex layer 111b functioning as the base composed of an i-Si1-xGex layer and a p+ Si1-xGex layer is formed on a collector layer 102, and a Si cap layer 111a as the emitter is formed on the p+ Si1-xGex layer. An emitter lead electrode 129, which is composed of an n− polysilicon layer 129b containing phosphorus in a concentration equal to or lower than the solid-solubility limit for single-crystal silicon and a n+ polysilicon layer 129a containing phosphorus in a high concentration, is formed on the Si cap layer 111a in a base opening 118. The impurity concentration distribution in the base layer is properly maintained by suppressing the Si cap layer 111a from being doped with phosphorus (P) in an excessively high concentration. The upper portion of the Si cap layer 111a may contain a p-type impurity. The p-type impurity concentration distribution in the base layer of an NPN bipolar transistor is thus properly maintained.