Abstract: Systems and methods for voltage distribution via epitaxial layers. In accordance with a first embodiment of the present invention, an integrated circuit comprises an epitaxial layer of a connectivity type disposed upon a wafer substrate of an opposite connectivity type.

Abstract: A semiconductor device using a CESL (contact etch stop layer) to induce strain in, for example, a CMOS transistor channel, and a method for fabricating such a device. A stress-producing CESL, tensile in an n-channel device and compressive in a p-channel device, is formed over the device gate structure as a discontinuous layer. This may be done, for example, by depositing an appropriate CESL, then forming an ILD layer, and simultaneously reducing the ILD layer and the CESL to a desired level. The discontinuity preferably exposes the gate electrode, or the metal contact region formed on it, if present. The upper boundary of the CESL may be further reduced, however, to position it below the upper boundary of the gate electrode.

Abstract: In a process of manufacturing elements of different structures and characteristics on the same substrate at the same time, the number of steps is increased and complicated. In view of this, the invention provides a semiconductor device and a manufacturing process thereof in which elements of different structures are formed on the same substrate while reducing the number of steps. According to the invention, in accordance with a memory transistor that requires the largest number of steps when being formed among elements that forms a semiconductor memory device, other high speed transistor and high voltage transistor are efficiently manufactured. Thus, the number of steps is suppressed and a low cost semiconductor memory device can be manufactured.

Abstract: Layout patterns for the deep well region to facilitate routing the body-bias voltage in a semiconductor device are provided and described. The layout patterns include a diagonal sub-surface mesh structure, an axial sub-surface mesh structure, a diagonal sub-surface strip structure, and an axial sub-surface strip structure. A particular layout pattern is selected for an area of the semiconductor device according to several factors.

Abstract: A CMOS transistor and a method of manufacturing the CMOS transistor are disclosed. An NMOS transistor is formed on a first region of a semiconductor substrate. A PMOS transistor is formed on a second region of a semiconductor substrate. The NMOS transistor includes a first gate conductive layer. The PMOS transistor includes a second gate conductive layer. The first gate conductive layer includes a metal having a nitrogen concentration increasing in a direction from a lower portion toward an upper portion. In addition, the metal has a work function of about 4.0 eV to about 4.3 eV. The third gate conductive layer includes a metal having a nitrogen concentration increasing in a direction from a lower portion toward an upper portion. In addition, the metal has a work function of about 4.7 eV to about 5.0 eV.

Abstract: A patterning method includes defining, in the case of an electric current which exceeds an allowable limit flowing between first conduction type well regions arranged in a semiconductor substrate, a first pattern between the first conduction type well regions; defining a second pattern by removing, in the case of a first region in which arrangement is inhibited being in the first pattern, the first region from the first pattern; defining a third pattern by removing, in the case of a second region which exceeds a fabrication limit being in the second pattern, the second region from the second pattern; and using the third pattern as a dummy active region in a second conduction type well region arranged in the semiconductor substrate.

Abstract: A method is disclosed for forming an STI (shallow trench isolation) in a substrate during CMOS (complementary metal-oxide semiconductor) semiconductor fabrication which includes providing at least two wells including dopants. A pad layer may be formed on a top surface of the substrate and a partial STI trench is etched in the upper portion of the substrate followed by etching to form a full STI trench. Boron is implanted in a lower area of the full STI trench forming an implant area which is anodized to form a porous silicon region, which is then oxidized to form a oxidized region. A dielectric layer is formed over the silicon nitride layer filling the full STI trench to provide, after etching, at least two electrical component areas on the top surface of the substrate having the full STI trench therebetween.

Abstract: A metal gate/high-k dielectric semiconductor device provides an NMOS gate structure and a PMOS gate structure formed on a semiconductor substrate. The NMOS gate structure includes a high-k gate dielectric treated with a dopant impurity such as La and the high-k gate dielectric material of the PMOS gate structure is deficient of this dopant impurity and further includes a work function tuning layer over the high-k gate dielectric. A process for simultaneously forming the NMOS and PMOS gate structures includes forming the high-k gate dielectric material, and the work function tuning layer thereover, then selectively removing the work function tuning layer from the NMOS region and carrying out a plasma treatment to selectively dope the high-k gate dielectric material in the NMOS region with a dopant impurity while the high-k gate dielectric in the PMOS region is substantially free of the dopant impurity.

Abstract: Dual thickness devices and circuits using dual gate thickness devices. The devices include: one or more FETs of a first polarity and one or more FETs of a second and opposite polarity, the one or more FETs of the first polarity electrically connected to the one or more FETs of the second polarity in a same circuit, at least one of the one or more FETs of the first polarity having a gate dielectric consisting of a single layer of thermal silicon oxide and having a thickness different from a thickness of a gate dielectric consisting of a single layer of thermal silicon oxide of at least one of the one or more FETs of the second polarity.

Abstract: Embodiments relate to a method of forming a 90 nm semiconductor device, including forming an isolation film within a semiconductor substrate in which a pMOS region and an nMOS region are defined. A first mask is formed to shield the nMOS region by using a DUV photoresist having a thickness of approximately 0.7 to 0.75 ?m. Ions are implanted into the pMOS region to form a p type well. A second mask is formed to shield the pMOS region by using a DUV photoresist having a thickness of approximately 0.7 to 0.75 ?m. Ions are implanted into the nMOS region to form an n type well. A gate oxide film and a gate is formed over the semiconductor substrate. A low-concentration impurity may be implanted by using the gate as a mask. An LDD region may be formed. A sidewall spacer may be formed over both sidewalls of the gate. A high-concentration impurity is implanted by using the sidewall spacer as a mask, forming a source/drain region.

Abstract: Exemplary embodiments provide structures for dual work function metal gate electrodes. The work function value of a metal gate electrode can be increased and/or decreased by disposing various electronegative species and/or electropositive species at the metal/dielectric interface to control interface dipoles. In an exemplary embodiment, various electronegative species can be disposed at the metal/dielectric interface to increase the work function value of the metal, which can be used for a PMOS metal gate electrode in a dual work function gated device. Various electropositive species can be disposed at the metal/dielectric interface to decrease the work function value of the metal, which can be used for an NMOS metal gate electrode in the dual work function gated device.

Abstract: A semiconductor device has an n-channel MIS transistor and a p-channel MIS transistor on a substrate. The n-channel MIS transistor includes a p-type semiconductor region formed on the substrate, a lower layer gate electrode which is formed via a gate insulating film above the p-type semiconductor region and which is one monolayer or more and 3 nm or less in thickness, and an upper layer gate electrode which is formed on the lower layer gate electrode, whose average electronegativity is 0.1 or more smaller than the average electronegativity of the lower layer gate electrode. The p-channel MIS transistor includes an n-type semiconductor region formed on the substrate and a gate electrode which is formed via a gate insulating film above the n-type semiconductor region and is made of the same metal material as that of the upper layer gate electrode.

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: The present invention provides a technique for reducing stress or stress gradients in highly sensitive device regions, such as cache areas, while still providing high transistor performance in logic areas by correspondingly providing contact etch stop layers with compressive and tensile stress for P-channel transistors and N-channel transistors in these logic areas. Consequently, a reduced failure rate may be obtained.

Abstract: Diagonal deep well region for routing the body-bias voltage for MOSFETS in surface well regions is provided and described.

Abstract: The present invention provides a semiconducting structure including a substrate having an SOI region and a bulk-Si region, wherein the SOI region and the bulk-Si region have a same or differing crystallographic orientation; an isolation region separating the SOI region from the bulk-Si region; and at least one first device located in the SOI region and at least one second device located in the bulk-Si region. The SOI region has an silicon layer atop an insulating layer. The bulk-Si region further comprises a well region underlying the second device and a contact to the well region, wherein the contact stabilizes floating body effects. The well contact is also used to control the threshold voltages of the FETs in the bulk-Si region to optimized the power and performance of circuits built from the combination of the SOI and bulk-Si region FETs.

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: The present invention is directed to CMOS structures that include at least one nMOS device located on one region of a semiconductor substrate; and at least one pMOS device located on another region of the semiconductor substrate. In accordance with the present invention, the at least one nMOS device includes a gate stack comprising a gate dielectric, a low workfunction elemental metal having a workfunction of less than 4.2 eV, an in-situ metallic capping layer, and a polysilicon encapsulation layer and the at least one pMOS includes a gate stack comprising a gate dielectric, a high workfunction elemental metal having a workfunction of greater than 4.9 eV, a metallic capping layer, and a polysilicon encapsulation layer. The present invention also provides methods of fabricating such a CMOS structure.

Abstract: A semiconductor structure includes a semiconductor substrate, a planar PMOS device at a surface of the semiconductor substrate, and an NMOS device at the surface of the semiconductor substrate, wherein the NMOS device is a Fin field effect transistor (FinFET).

Abstract: A semiconductor device including a first field effect transistor having a source, a first conductivity type drain, a gate, and a first conductivity type channel layer formed beneath the gate and between the source and the drain. The device also includes a first conductivity type well region, a second conductivity type channel layer formed on the surface of the well region, a first wire that connects an end of the second conductivity type channel layer to the first conductivity type drain, a second wire that connects the other end of the second conductivity type channel layer to a power source, and a third wire 208 that connects the first conductivity type well region to the gate of the first field effect transistor. This semiconductor device and manufacturing method thereof enables low power consumption and simple control of threshold voltage values as well as decreases the number of conventional manufacturing processes.

Abstract: A method and device for image sensing. The method includes forming a first well and a second well in a substrate, forming a gate oxide layer on the substrate, and depositing a first gate region and a second gate region on the gate oxide layer. The first gate region is associated with the first well, and the second gate region is associated with the second well. Additionally, the method includes forming a third well in the substrate, implanting a first plurality of ions to form a first lightly doped source region and a first lightly doped drain region in the first well, implanting a second plurality of ions to form at least a second lightly doped drain region in the second well, and implanting a third plurality of ions to form a source in the second well.

Abstract: Embodiments herein present device, method, etc. for a hybrid orientation scheme for standard orthogonal circuits. An integrated circuit of embodiments of the invention comprises a hybrid orientation substrate, comprising first areas having a first crystalline orientation and second areas having a second crystalline orientation. The first crystalline orientation of the first areas is not parallel or perpendicular to the second crystalline orientation of the second areas. The integrated circuit further comprises first type devices on the first areas and second type devices on the second areas, wherein the first type devices are parallel or perpendicular to the second type devices. Specifically, the first type devices comprise p-type field effect transistors (PFETs) and the second type devices comprise n-type field effect transistors (NFETs).

Abstract: A family of semiconductor devices is formed in a substrate that contains no epitaxial layer. In one embodiment the family includes a 5V CMOS pair, a 12V CMOS pair, a 5V NPN, a 5V PNP, several forms of a lateral trench MOSFET, and a 30V lateral N-channel DMOS. Each of the devices is extremely compact, both laterally and vertically, and can be fully isolated from all other devices in the substrate.

Abstract: A technique which can improve manufacturing yield and product reliability is provided in a semiconductor device having a triple well structure. An inverter circuit which includes an n-channel type field effect transistor formed in a shallow p-type well and a p-channel type field effect transistor formed in a shallow n-type well, and does not contribute to circuit operations is provided in a deep n-type well formed in a p-type substrate; the shallow p-type well is connected to the substrate using a wiring of a first layer; and the gate electrode of the p-channel type field effect transistor and the gate electrode of the n-channel type field effect transistor are connected to the shallow n-type well using a wiring of an uppermost layer.

Abstract: An integrated transistor device is formed in a chip of semiconductor material having an electrical-insulation region delimiting an active area accommodating a bipolar transistor of vertical type and a MOSFET of planar type, contiguous to one another. The active area accommodates a collector region; a bipolar base region contiguous to the collector region; an emitter region within the bipolar base region; a source region, arranged at a distance from the bipolar base region; a drain region; a channel region arranged between the source region and the drain region; and a well region. The drain region and the bipolar base region are contiguous and form a common base structure shared by the bipolar transistor and the MOSFET. Thereby, the integrated transistor device has a high input impedance and is capable of driving high currents, while only requiring a small integration area.

Abstract: A mixed voltage circuit is formed by providing a substrate (12) having a first region (20) for forming a first device (106), a second region (22) for forming a second device (108) complementary to the first device (106), and a third region (24) for forming a third device (110) that operates at a different voltage than the first device (106). A gate layer (50) is formed outwardly of the first, second, and third regions (20, 22, 24). While maintaining a substantially uniform concentration of a dopant type (51) in the gate layer (50), a first gate electrode (56) is formed in the first region (20), a second gate electrode (58) is formed in the second region (22), and a third gate electrode (60) is formed in the third region (24). The third region (24) is protected while implanting dopants (72) into the first region (20) to form source and drain features (74) for the first device (106).

Abstract: In accordance with an embodiment of the invention, there is an integrated circuit device having a complementary integrated circuit structure comprising a first MOS device. The first MOS device comprises a source doped to a first conductivity type, a drain extension doped to the first conductivity type separated from the source by a gate, and an extension region doped to a second conductivity type underlying at least a portion of the drain extension adjacent to the gate. The integrated circuit structure also comprises a second complementary MOS device comprising a dual drain extension structure.

Abstract: A semiconductor device may include a semiconductor substrate having a first region and a second region. The nitrogen-incorporated active region may be formed within the first region. A first gate electrode may be formed on the nitrogen-incorporated active region. A first gate dielectric layer may be interposed between the nitrogen-incorporated active region and the first gate electrode. The first gate dielectric layer may include a first dielectric layer and a second dielectric layer. The second dielectric layer may be a nitrogen contained dielectric layer. A second gate electrode may be formed on the second region. A second gate dielectric layer may be interposed between the second region and the second gate electrode. The first gate dielectric layer may have the same or substantially the same thickness as the second gate dielectric layer, and the nitrogen contained dielectric layer may contact with the nitrogen-incorporated active region.

Abstract: A method for manufacturing a device includes mapping extreme vertical boundary conditions of a mask layer based on vertical edges of a deposited first layer and a second layer. The mask layer is deposited over portions of the second layer based on the mapping step. The exposed area of the second layer is etched to form a smooth boundary between the first layer and the second layer. The resist layer is stripped. The resulting device is an improved PFET device and NFET device with a smooth boundary between the first and second layers such that a contact can be formed at the smooth boundary without over etching other areas of the device.

Abstract: A semiconductor device including an isolation region located in a substrate, an NMOS device located partially over a surface of the substrate, and a PMOS device isolated from the NMOS device by the isolation region and located partially over the surface. A first one of the NMOS and PMOS devices includes one of: (1) first source/drain regions recessed within the surface; and (2) first source/drain regions extending from the surface. A second one of the NMOS and PMOS devices includes one of: (1) second source/drain regions recessed within the surface wherein the first source/drain regions extend from the surface; (2) second source/drain regions extending from the surface wherein the first source/drain regions are recessed within the surface; and (3) second source/drain regions substantially coplanar with the surface.

Abstract: A semiconductor device is provided which is capable of avoiding malfunction and latchup breakdown resulting from negative variation of high-voltage-side floating offset voltage (VS). In the upper surface of an n-type impurity region, a p+-type impurity region is formed between an NMOS and a PMOS and in contact with a p-type well. An electrode resides on the p+-type impurity region and the electrode is connected to a high-voltage-side floating offset voltage (VS). The p+-type impurity region has a higher impurity concentration than the p-type well and is shallower than the p-type well. Between the p+-type impurity region and the PMOS, an n+-type impurity region is formed in the upper surface of the n-type impurity region. An electrode resides on the n+-type impurity region and the electrode is connected to a high-voltage-side floating supply absolute voltage (VB).

Abstract: A semiconductor integrated circuit has a first substrate of a first polarity to which a first substrate potential is given, a second substrate of the first polarity to which a second substrate potential different from the first substrate potential is given, and a third substrate of a second polarity different from the first polarity. The first substrate is insulated from a power source or ground to which a source of a MOSFET formed on the substrate is connected. The third substrate is disposed between the first and second substrates in adjacent relation to the first and second substrates. A circuit element is formed on the third substrate.

Abstract: A semiconductor device includes a substrate, an epitaxial layer, a sinker, an active device, a first buried layer, and a second buried layer. The substrate has a first type conductivity. The epitaxial layer has a second type conductivity, and is located on the substrate. The sinker has the second type conductivity, and is located in the epitaxial layer. The sinker extends from the substrate to an upper surface of the epitaxial layer, and partitions a region off from the epitaxial layer. The active device is located within the region. The first buried layer has the first type conductivity, and is located between the region and the substrate. The second buried layer has the second type conductivity, and is located between the first buried layer and the substrate. The second buried layer connects with the sinker. Because of the above-mentioned configuration, latch-up can be prevented.

Abstract: One aspect of the invention provides a semiconductor device that includes gate electrodes comprising a metal or metal alloy located over a semiconductor substrate, wherein the gate electrodes are free of spacer sidewalls. The device further includes source/drains having source/drain extensions associated therewith, located in the semiconductor substrate and adjacent each of the gate electrodes. A first pre-metal dielectric layer is located on the sidewalls of the gate electrodes and over the source/drains, and a second pre-metal dielectric layer is located on the first pre-metal dielectric layer. Contact plugs extend through the first and second pre-metal dielectric layers.

Abstract: A element isolation insulating film is formed around the device regions in the silicon substrate. The device regions are formed an n-type diffusion layer region, a p-type diffusion layer region, a p-type extension region, an n-type extension region, a p-type source/drain region, an n-type source/drain region, and a nickel silicide film. Each gate dielectric film is made up of a silicon oxide film and a hafnium silicon oxynitride film. The n-type gate electrode is made up of an n-type silicon film and a nickel silicide film, and the p-type gate electrode is made up of a nickel silicide film. The hafnium silicon oxynitride films are not formed on the sidewalls of the gate electrodes.

Abstract: A vertical transistor having a wrap-around-gate and a method of fabricating such a transistor. The wrap-around-gate (WAG) vertical transistors are fabricated by a process in which source, drain and channel regions of the transistor are automatically defined and aligned by the fabrication process, without photolithographic patterning.

Abstract: A high-voltage MOS device includes a first high-voltage well (HVW) region overlying a substrate, a second HVW region overlying the substrate, a third HVW region of an opposite conductivity type as that of the first and the second HVW regions overlying the substrate, wherein the HVPW region has at least a portion between the first HVNW region and the second HVNW region, an insulation region in the first HVNW region, the second HVNW region, and the HVPW region, a gate dielectric over and extending from the first HVNW region to the second HVNW region, a gate electrode on the gate dielectric, and a shielding pattern electrically insulated from the gate electrode over the insulation region. Preferably, the gate electrode and the shielding pattern have a spacing of less than about 0.4 ?m. The shielding pattern is preferably connected to a voltage lower than a stress voltage applied on the gate electrode.

Abstract: A permeation preventing film of a silicon nitride film 16 is inserted between a silicon substrate 10 and a High-k gate insulation film 18 to thereby prevent the High-k gate insulation film 18 from being deprived of oxygen, while oxygen anneal is performed after a gate electrode layer 20 has been formed to thereby supplement oxygen. The silicon nitride film 16, which is the permeation preventing film, becomes a silicon oxide nitride film 17 without changing the film thickness, whereby characteristics deterioration of the High-k gate insulation film 18 due to the oxygen loss can be prevented without lowering the performance of the transistor. The semiconductor device having the gate insulation film formed of even a high dielectric constant material can be free from the shift of the threshold voltage.

Abstract: In a semiconductor substrate of a first conductivity type, a first well region of the first conductivity type, second well regions of a second conductivity type, and a third well region of the second conductivity type are formed. The second well regions are formed in the semiconductor substrate excluding the region where the first well region has been formed. The third well region is formed under the first and second well regions in the semiconductor substrate in such a manner that a part of the third well region under the first well region is removed, thereby connecting the second well regions to one another electrically.

Abstract: A technique for and structures for camouflaging an integrated circuit structure. The integrated circuit structure is formed having a well of a first conductivity type under the gate region being disposed adjacent to active regions of a first conductivity type. The well forming an electrical path between the active regions regardless of any reasonable voltage applied to the integrated circuit structure.

Abstract: The channels of first and second CMOS transistors can be selectively stressed. A gate structure of the first transistor includes a stressor that produces stress in the channel of the first transistor. A gate structure of the second transistor is disposed in contact with a layer of material that produces stress in the channel of the second transistor.

Abstract: A semiconductor integrated circuit comprising: a pair of MOS transistors which are formed in a same well on a semiconductor substrate and arranged adjacent to each other with a distance such that charge exchange between capacitances of respective drain diffusion layers is possible; and a wiring structure which is formed to apply differential signals to respective gates of the pair of MOS transistors and to apply a common potential to respective sources of the pair of MOS transistors.

Abstract: Structures and methods of manufacturing are disclosed of dislocation free stressed channels in bulk silicon and SOI (silicon on insulator) CMOS (complementary metal oxide semiconductor) devices by gate stress engineering with SiGe and/or Si:C. A CMOS device comprises a substrate of either bulk Si or SOI, a gate dielectric layer over the substrate, and a stacked gate structure of SiGe and/or Si:C having stresses produced at the interfaces of SSi(strained Si)/SiGe or SSi/Si:C in the stacked gate structure. The stacked gate structure has a first stressed film layer of large grain size Si or SiGe over the gate dielectric layer, a second stressed film layer of strained SiGe or strained Si:C over the first stressed film layer, and a semiconductor or conductor such as p(poly)-Si over the second stressed film layer.

Abstract: A method for manufacturing a semiconductor device, including etching exposed areas of a substrate using patterned nitride and insulating layers as an etch mask to form a trench in the substrate; forming a buffer layer in the trench; forming a stress-inducing layer by implanting ions into a region of the substrate around the trench using the patterned nitride and insulating layers as an ion implant mask; forming a device isolation region by filling the trench with an trench insulating layer; and removing the patterned nitride and insulating layers.

Abstract: A semiconductor device and method of manufacturing a semiconductor device. The semiconductor device includes channels for a pFET and an nFET. An SiGe layer is grown in the channel of the nFET channel and a Si:C layer is grown in the pFET channel. The SiGe and Si:C layer match a lattice network of the underlying Si layer to create a stress component in an overlying grown epitaxial layer. In one implementation, this causes a compressive component in the pFET channel and a tensile component in the nFET channel. In a further implementation, the SiGe layer is grown in both the nFET and pFET channels. In this implementation, the stress level in the pFET channel should be greater than approximately 3 GPa.

Abstract: A logic book for a programmable device such as an application-specific integrated circuit (ASIC) achieves improved radiation tolerance by providing notches in an implant well between adjacent transistors and fills the notches with complementary well regions that act as a barrier to charge migration. For example, a row of n-type field effect transistors (NFETs) is located in a Pwell region, while a row of p-type transistors is located in an Nwell region with portions of the Nwell region extending between the NFETs. More complicated embodiments of the present invention include embedded well islands to provide barriers for adjacent transistors in both rows of the book.

Abstract: A semiconductor integrated circuit has complementary field-effect transistors, one formed in a semiconductor substrate, the other formed in a well in the substrate, and has four power-supply potentials: two supplied to the sources of the field-effect transistors, one supplied to the substrate, and one supplied to the well. An unwanted pair of parasitic bipolar transistors are formed in association with the field-effect transistors. An intentionally formed bipolar transistor operates in series with one of the unwanted parasitic transistors and as a current mirror for the other unwanted parasitic transistor, limiting the flow of unwanted current through the parasitic bipolar transistors.