Abstract: An integrated digital circuit is protected from reverse engineering by fabricating all transistors of like conductivity with a common size and geometric layout, providing a common layout for different logic cells, connecting doped circuit elements of like conductivity with electrically conductive doped implants in the substrate rather than metalized interconnections, and providing non-functional apparent interconnections that are interrupted by non-discernable channel stops so that all cells falsely appear to have a common interconnection scheme. The camouflage is enhanced by providing a uniform pattern of metal leads over the transistor array, with a uniform pattern of heavily doped implant taps from the transistors for connection to the leads; undesired tap-lead connections are blocked by channel stops.

Abstract: The present invention discloses a semiconductor device having a triple well structure. The semiconductor device includes a N-type impurity doped buried layer, formed in the semiconductor substrate at a predetermined depth from the surface of the first active region; a first P-type well region formed beneath the second active region which is adjacent to the first active region; a second P-type well region formed in the semiconductor substrate to a depth from the surface of the first active region; a first N-type well region formed beneath the third active region; a second N-type well region formed beneath selected portion of the isolation film defining first active region and the second active region; and a first P-type doping region and a second N-type doping region formed respectively right beneath the surface of the first active region and right beneath the surface of the second active region, wherein the dopant concentration of the first doping region is lower than that of the second doping region.

Abstract: In a semiconductor device and a method of manufacturing the same according to the present invention, a trade-off relationship between threshold values and a diffusion layer leakage is eliminated and it is not necessary to form gate oxide films at more than one stages. Since doses of nitrogen are different from each other between gate electrodes (4A to 4C) of N-channel type MOS transistors (T41 to T43), concentrations of nitrogen in the nitrogen-introduced regions (N1 to N3) are accordingly different from each other. Concentrations of nitrogen in the gate electrodes are progressively lower in the order of expected higher threshold values.

Abstract: An IC comprises a tub of a first conductivity type, at least one transistor embedded in the tub, and a first pair of isolating regions defining therebetween a tub-tie region coupled to the tub. The tub-tie region comprises a cap portion of the first conductivity type and an underlying buried pedestal portion of a second conductivity type. At least a top section of the pedestal portion is surrounded by the cap portion so that a conducting path is formed between the cap portion and the tub. In a CMOS IC tub-ties of this design are provided for both NMOS and PMOS transistors. In a preferred embodiment, the cap portion of each tub-tie comprises a relatively heavily doped central section and more lightly doped peripheral sections, both of the same conductivity type.

Abstract: The present invention discloses a semiconductor device having a triple well structure. The semiconductor device includes a N-type impurity doped buried layer, formed in the semiconductor substrate at a predetermined depth from the surface of the first active region; a first P-type well region formed beneath the second active region which is adjacent to the first active region; a second P-type well region formed in the semiconductor substrate to a depth from the surface of the first active region; a first N-type well region formed beneath the third active region; a second N-type well region formed beneath selected portion of the isolation film defining first active region and the second active region; and a first P-type doping region and a second N-type doping region formed respectively right beneath the surface of the first active region and right beneath the surface of the second active region, wherein the dopant concentration of the first doping region is lower than that of the second doping region.

Abstract: In a semiconductor device having a PN junction element separating region, in order to reduce a width of the PN junction element separating region without sacrifice of a punch-through breakdown voltage of the PN junction element separating region, the PN junction element separating region is composed of an upper impurity layer of a first conductivity type having low impurity density and a lower impurity layer of the first conductivity type having a high impurity density and a width of the upper impurity layer is smaller than a width of the lower impurity layer.

Abstract: The present invention provides a semiconductor device which includes a substrate having a projection-shaped semiconductor element region, a gate electrode formed through a gate insulating film on the upper face and side face of the element region, and a first conductivity type source region and drain region provided in a manner to form a channel region on the upper face of the element region across the gate electrode, and which has a high concentration impurity region containing a second conductivity type impurity at a concentration higher than that on the surface of the channel region in the central part of the projection-shaped semiconductor element region.

Abstract: A semiconductor device includes a flat, square n-type diffusion layer, a p-type channel stopper region, and an electrode. The n-type diffusion layer is formed to be isolated in a check element region of a p-type semiconductor substrate or a p-type well covered with a field oxide film and having circuit element regions and the check element region sandwiched therebetween. The p-type channel stopper region is formed to contact at least one side of the n-type diffusion layer. The electrode is extracted from the n-type diffusion layer through a contact hole. The n-type diffusion layer, the p-type channel stopper region, and the electrode constitute the check element for checking a state of the p-type channel stopper region by measuring a junction breakdown voltage of the n-type diffusion layer.

Abstract: CMOS vertically modulated wells are constructed by using a blanket implant to form a blanket buried layer and then using clustered MeV ion implantation to form a structure having a buried implanted layer for lateral isolation in addition to said blanket buried layer.

Abstract: The invention is a method for creating a portion of an integrated circuit on a semiconductor wafer. The invention comprises doping a substrate to form a doped well region having an opposite conductivity type than the substrate. Separate photomasking steps are used to define N-channel and P-channel metal oxide semiconductor (MOS) transistor gates. A trench is formed near the well without using additional masking steps. The trench improves the latch up immunity of the device. The invention is also the apparatus created by the method and comprises a trench positioned in the substrate to interrupt the conduction of minority carriers between two regions of the substrate. Thus, the invention improves latch up immunity without additional process complexity.

Abstract: A low-voltage 0.8-micron CMOS process is modified by implanting arsenic or phosphorus during epitaxy in a p-type substrate starting material to increase the depth of selected n-well areas for the purpose of producing high-voltage transistors on the same substrate in the same CMOS process. Implanting boron in a p-field extension area in a manner which minimizes the dopant in the adjacent field oxide achieves a similar result. That is, breakdown and punch-through voltages are increased. Together, these make CMOS transistors which operate at a higher voltage range than either innovation alone.

Abstract: A manufacturing method for a semiconductor device is disclosed for effecting improvement of voltage resistance between an N-well and N-type diffusion layer without adversely affecting circuit and transistor characteristics. At the time of forming an N-well, a side wall composed of nitride layer is formed on the oxide layer that is used as a mask in phosphorus implantation, and the N-well is formed using as a mask the oxide layer on which this side wall is provided. The side wall is then removed, boron is implanted, and a channel stopper is formed only between the N-well and N-type diffusion layer. A channel stopper between N-type diffusion layers is formed subsequently as a separate step. In this way, the concentration of the channel stopper between the N-well and N-type diffusion can be set to a concentration different from that of the channel stopper between N-type diffusion layers.

Abstract: An integrated circuit includes an N isolation buried layer underlying high density and low voltage type P channel and N channel transistors to define islands of arbitrary voltage on the substrate. Thus such transistors, which otherwise are capable only of low voltage operation, become capable of operating at high voltage relative to the substrate. This allows integration, on a single chip, of high voltage circuit elements with low voltage and high density transistors all formed by the same fabrication process sequence. In one example this allows creation of an 18 volt range charge pump using a CMOS process which normally provides only 3 volt operating range transistors. This then allows integration on a single integrated circuit chip of a complex digital logic function such as a UART (universal asynchronous receiver and transmitter) with a high voltage function such as an RS-232 interface, including integrated capacitors for the RS-232 interface charge pump.

Abstract: A semiconductor processing method of forming complementary metal oxide semiconductor memory circuitry includes, a) defining a memory array area and a peripheral area on a bulk semiconductor substrate, the peripheral area including a p-well area for formation of NMOS peripheral circuitry, the peripheral area including a first n-well area and a second n-well area for formation of respective PMOS peripheral circuitry, the first and second n-well areas being separate from one another and having respective peripheries; b) providing a patterned masking layer over the substrate relative to the peripheral first and second n-wells, the masking layer including a first masking block overlying the first n-well and a second masking block overlying the second n-well, the first masking block masking a lateral edge of the first n-well periphery; and c) with the first and second masking blocks in place, providing a buried n-type electron collector layer by ion implanting into the bulk substrate; the resultant n-type electron

Abstract: A method of forming CMOS integrated circuitry includes, a) providing a series of gate lines over a semiconductor substrate, a first gate line being positioned relative to an area of the substrate for formation of an NMOS transistor, a second gate line being positioned relative to an area of the substrate for formation of a PMOS transistor; b) masking the second gate line and the PMOS substrate area while conducting a p-type halo ion implant into the NMOS substrate area adjacent the first gate line, the p-type halo ion implant being conducted at a first energy level to provide a p-type first impurity concentration at a first depth within the NMOS substrate area; and c) in a common step, blanket ion implanting phosphorus into both the NMOS substrate area and the PMOS substrate area adjacent the first and the second gate lines to form both NMOS LDD regions and PMOS n-type halo regions, respectively, the phosphorus implant being conducted at a second energy level to provide an n-type second impurity concentration

Abstract: A CMOS integrated circuit with field isolation including an NFET(s) having an isolated P-well, wherein the isolated P-well is adjusted so that it does not extend below the field isolation (e.g., STI) and the width and doping of the P-well and an underlying buried N-well is adjusted so that the depletion regions of the source/drain (S-D) diode and also the well-diode just meet (merge) without overlap in the P-well. The semiconductor device obtains bipolar effect and reduced junction capacitance in a bulk single-crystal technology. A method for fabricating the semiconductor device if also provided.

Abstract: The invention provides an n-channel MOS field effect transistor with an improved anti-radioactivity. Such transistor includes a p-type silicon substrate. An isolation oxide film is selectively formed on a surface of the p-type silicon substrate. Source and drain diffusion layers of n+-type are formed on first opposite sides of a channel region in the p-type silicon substrate. A gate made of polycrystalline silicon is formed over the channel region through a gate oxide film. Leak guard diffusion layers of p-type are formed on second opposite sides of the channel region in the p-type silicon substrate. The p-type leak guard diffusion layer has a junction surface to the isolation oxide film. The junction surface of the p-type leak guard diffusion layer and the isolation oxide film exists up to a level which is deeper than a depth of the n+-type source and drain diffusion layers.

Abstract: A graded-channel semiconductor device (10) includes a substrate region (11) having a major surface (12). A source region (13) and a drain region (14) are formed in the substrate region (11) and are spaced apart to form a channel region (16). A doped region (18) is formed in the channel region (16) and is spaced apart from the source region (13), the drain region (14), and the major surface (12). The doped region (18) has the same conductivity type as the channel region (16), but has a higher dopant concentration. The device (10) exhibits an enhanced punch-through resistance and improved performance compared to prior art short channel structures.

Abstract: In IGBTs or, respectively, MOSFETs a parasitic junction-FET effect can be nearly avoided on the basis of an insulation layer introduced between the two base zones and into which an electrode is additionally embedded. The on-resistance is lowered as a result thereof. In an advantageous development, a potential activation of the parasitic bipolar structure (latch-up) can also be prevented.

Abstract: Local interconnect structures and processes using dual-doped polysilicon. A single implant dopes part of the polysilicon local interconnect layer p-type, and also diffuses through the polysilicon interconnect layer to enhance the doping of the PMOS drain regions, and also (optionally) adds to the doping of the PMOS source regions to provide source/drain asymmetry. The polysilicon interconnect layer is clad to reduce its conductivity, optionally with patterned rather than global cladding so that the diode can be used as a load element if desired.

Abstract: An active pixel image sensor in accordance with the present invention utilizes guard rings, protective diffusions, and/or a combination of these two techniques to prevent electrons generated at the periphery of the active area from impacting upon the image sensor array. For example, an n+ guard ring connected to V.sub.cc can be imposed in the p-epi layer between the active area edge and the array, making it difficult for edge-generated electrons to penetrate the p+ epi in the array; this approach requires the use of annular MOS devices in the array. Alternatively, the gates of the n-channel devices in the array can be built to overlap heavily doped p+ bands, forcing current flow between the source/drain regions. As stated above, combinations of these two techniques are also contemplated. Elimination of the active area edge leakage component from the array can increase the dynamic range of the image sensor by 6 bits.

Abstract: The concentration of impurities at the surface of the semiconductor device adjacent and under the bird's beak of a field oxide region is reduced by employing sidewall spacers prior to field implantation. The resulting semiconductor device exhibits reduced sidewall junction capacitance and leakage, an increased junction breakdown voltage and a reduced narrow channel effect.

Abstract: A low-voltage 0.8-micron CMOS process is modified by implanting arsenic or phosphorus during epitaxy in a p-type substrate starting material to increase the depth of selected n-well areas for the purpose of producing high-voltage transistors on the same substrate in the same CMOS process. Implanting boron in a p-field extension area in a manner which minimizes the dopant in the adjacent field oxide achieves a similar result. That is, breakdown and punch-through voltages are increased. Together, these make CMOS transistors which operate at a higher voltage range than either innovation alone.

Abstract: Dielectrically isolated semiconductor devices such as DMOS and ZGBT devices comprise a substrate having upper and lower surfaces. Source, drain and channel regions are disposed along the upper surface. The drain region extends downwardly to the lower surface of the substrate and laterally beneath the source and channel region. The drain merges with an underlying region of high conductivity. The underlying region is generally flat except for an upwardly extending portion thereof laterally disposed from the source region and providing a lower resistance path for current through the drain region. The DMOS devices can be included within an integrated circuit chip containing other types of semiconductor devices.

Abstract: An N-channel and P-channel MOSFET include counterdoping of a threshold voltage (V.sub.T) ion implant for reducing substrate sensitivity and source/drain junction capacitance. An arsenic (As) compensated boron (B) implant is provided in the N-channel MOSFET. A boron (B) compensated arsenic (As) implant is provided in the P-channel MOSFET.

Abstract: A semiconductor device has an inherent region of the same conductivity type and the same impurity concentration as a semiconductor substrate and well regions located close to each other under a main surface of the semiconductor substrate. A field oxide film is selectively formed on the main surface. A MOSFET, termed an "undoped MOSFET," is formed in the inherent region. A carrier stop layer having a conductivity type opposite to, and an impurity concentration higher than, that of the inherent region is formed within the inherent region. The carrier stop layer extends from the bottom of the field oxide film and underlies the source/drain regions of the undoped MOSFET in spaced relationship therewith. The carrier stop layer prevents punch-through between the well region and densely diffused source/drain regions in the undoped MOSFET region, even when they are located close to each other.

Abstract: A semiconductor device in which ability for isolating elements from each other can be improved and increase in substrate constant and junction capacitance can be suppressed, is disclosed. An impurity layer for improving the ability for isolating elements is positioned only immediately below an isolating insulating film. An impurity layer for adjusting substrate constant and junction capacitance is formed through independent steps from the impurity layer for improving the isolating ability.

Abstract: An insulated gate field effect transistor which may be of the thin film type including a non-single crystalline semiconductor layer containing hydrogen or a halogen and having an intrinsic conductivity type. The semiconductor layer is disposed over a substrate including a channel region disposed in the semiconductor layer. Source and drain regions form respective junctions with the channel region where the channel region is disposed between the source and drain regions whereby charge carriers move through the channel region between the source and drain regions in a path substantially parallel to said substrate. A gate insulating film contacts the channel region and includes silicon and nitrogen. A gate electrode contacts the gate insulating film. At least a portion of the channel region contains at least one of oxygen, nitrogen, and carbon in an amount of not exceeding 5.times.10.sup.18 atoms/cm.sup.3.

Abstract: Region forming steps or interconnect-forming steps through which low voltage CMOS devices are formed in a semiconductor wafer are also employed to simultaneously form one or more regions or layers at selected sites of a substrate where high voltage devices are to be formed. Such selective modification of an already existing mask set designed for low voltage CMOS typography allows additional doping of the substrate or provision of further overlay material to accommodate the effects of high voltage operation of selected areas of the wafer and thereby effectively performs precursor tailoring or modification of those portions of the wafer where a high voltage condition will be encountered.

Abstract: A method for forming field oxide regions on an integrated circuit device includes the steps of providing doped regions for formation of active devices. After the doped regions have been formed, a thick field oxide layer is grown over the entire surface of the device. Field oxide regions are then defined using masking and anisotropic etching steps which provide approximately vertical sidewalls for the field oxide regions, and which do not result in the formation of bird's beaks. Since the active regions are defined prior to formation of the field oxide regions, the active regions extend under the field oxide regions and do not give rise to edge effects.

Abstract: A multi-channel type intelligent power IC which solves the problems of parasitic transistor and increase in an area of isolation region, both of which are inherent problem in a pn junction isolation substrate. The power IC also enhances heat-radiation performance. An n type first semiconductor substrate and p type second semiconductor substrate are directly bonded, and a buried oxide film is formed in a portion of a bonding interface thereof. Subsequently, a plurality of isolation trenches are formed and the first semiconductor substrate is separated into an SOI isolation region and a pn isolation region. Logic elements are then formed in the SOI isolation region, and power elements are formed in the pn isolation region. In the case wherein two or more logic elements are hereby formed, the logic elements are isolated by isolation trenches. In the case wherein two or more power elements are formed, a parasitic current extracting portion is formed between mutual power elements.

Abstract: An insulated gate bipolar transistor has a reverse conducting function built therein. A semiconductor layer of a first conduction type is formed on the side of a drain, a semiconductor layer of a second conduction type for causing conductivity modulation upon carrier injection is formed on the semiconductor layer of the first conduction type, a semiconductor layer of the second conduction type for taking out a reverse conducting current opposite in direction to a drain current is formed in the semiconductor layer of the second conduction type which is electrically connected to a drain electrode, and a semiconductor layer of the second conduction type is formed at or in the vicinity of a pn junction, through which carriers are given and received to cause conductivity modulation, with a high impurity concentration resulting in a path for the reverse conducting current into a pattern not impeding the passage of the carriers.

Abstract: A semiconductor MOSFET device manufactured by a process starting with a doped semiconductor substrate with a P-well and an N-well and field oxide structures on the surface of the P-well and the N-well separating the surfaces of the P-well and the N-well into separate regions and a silicon dioxide film on the remainder of the surface of the P-well and the N-well comprising the steps as follows: forming a mask over the N-well and an under sized mask over one of the separate regions of the P-well performing a field ion implantation of V.sub.t ' ions into the P-well, removing the mask over the portion of the P-well, performing a blanket ion implantation of V.sub.t1 ions over the entire device.

Abstract: An integrated circuit device (10) is provided that comprises an P-FET (12) and an N-FET (14) formed on a semiconductor substrate (32). The P-FET (12) is formed in an n- tank (46). The source (18) and back-gate contact (22) of the P-FET (12) are connected to the V.sub.DD supply voltage. A current sink region (50) is formed in contact with the bulk semiconductor substrate (32). Periodic back-gate contacts (30) and (52) are made to the current sink region (50). The source (26) of N-FET (14) is also connected to the back-gate contacts (30) and (52). The current sink region (50) provides a low resistance path for charge within the substrate (32) to paths to the supply voltage V.sub.SS. This low resistance path prevents voltage from building up in the substrate (32) and thereby prevents latchup from occurring.

Abstract: The semiconductor device contains a CMOS transistor pair comprised of a P channel MOS transistor having a polysilicon gate 4 and an N channel MOS transistor having a polysilicon gate. The MOS transistor has a channel dope layer 5 localized in a vicinity of a surface of a channel region just below a gate electrode. This channel dope layer 5 has a quite shallow p-n junction depth xj effective to suppress a leak current. Thereby, an amount of impurity concentration in the surface of the channel region can be reduced to improve a subthreshold characteristics of the MOS transistor and to enable a low voltage and high speed operation under suppressing a leakage current.

Abstract: An insulated gate semiconductor device such as a MOSFET realizes high-frequency high-output operations. A first main electrode (1a) set at grounding potential is Formed on the bottom surface of a substrate. A second main electrode region (4) set at power source potential is formed on the top surface of the substrate. This structure involves very low grounding inductance. A buried insulation film (9) is formed under the second main electrode region, to reduce capacitance and improve power gains at high frequencies. Unlike an ordinary SOI semiconductor device, the buried insulation film of this MOSFET is not entirely formed through the substrate. A conductive region (10) is formed from the top surface to the bottom surface of the substrate at a location where the insulation film is not present, to improve heat dissipation and provide high output power. The buried insulation film (9) is formed by SIMOX, buried epitaxy, or silicon direct bonding (SDB) method.

Abstract: The present invention is mainly characterized in that a semiconductor device having a well which is of the same conductivity type as that of a substrate and which is isolated from the substrate is improved not to cause interference between the well and the substrate even if a large amount of minority carriers are implanted. The semiconductor device is provided with a semiconductor substrate of the first conductivity type having the main surface. A first well of a first conductivity type is provided in the main surface of the semiconductor substrate. The first well, having side portions and a bottom portion, extends from the main surface. A second well of a second conductivity type is provided in the main surface of the semiconductor substrate so as to surround the side portions and the bottom portion of the first well. The bottom portion of the second well has a crystal defect region.

Abstract: An element separating oxide film is formed in a surface of a p-type silicon substrate for separation of an element forming region. A p-type impurity diffusion region extends from the vicinity of a lower surface of the element separating oxide film to a position at a predetermined depth in the element forming region. The p-type impurity diffusion region has a peak of concentration of impurity. In the element forming region adjacent to the element separating oxide film, an n.sup.+ impurity diffusion region is formed on the surface of the p-type silicon substrate. An n.sup.- impurity diffusion region adjacent to the n.sup.+ impurity diffusion region is formed between the n.sup.+ impurity diffusion region and the p-type impurity diffusion region.

Abstract: A CMOS circuit formed in a semiconductor substrate having improved immunity to radiation induced latch-up and improved immunity to a single event upset. The circuit architecture of the present invention can be utilized with N-Well, P-Well and dual Well processes. For example, the circuit is described relative to an N-Well process. An N-Well is formed in a p-type substrate. A network of p-channel transistors are formed in the N-Well and a network of n-channel transistors are formed in the p-type substrate. A continuous P+guard ring is formed surrounding the n-channel transistors and between the n-channel transistors and the N-Well. Similarly, a continuous N+guard ring is formed surrounding the p-channel transistors and between the p-channel transistors and the p-type substrate. In the event of a radiation hit, the guard rings operate to reduce the parasitic impedance in the collector circuits of the parasitic bipolars forming a parasitic SCR and also act as additional collectors of radiation induced current.

Abstract: A self-cascoding transconductance circuit has cascoding and current sink/source FETs, serially connected with their gates tied together to receive an input voltage, wherein the cascoding FET has a threshold voltage having an absolute value at least 0.1 volts less than that of the current sink/source FET to ensure that the current sink/source FET operates in its saturated region. A CMOS structure implementing the self-cascoding transconductance circuit has two doped threshold adjust regions formed beneath a gate electrode such that the two doped threshold adjust regions respectively effectuate the cascode and current sink/source FETs which then share the gate electrode. A method of forming the CMOS structure includes forming two self-cascoding transconductance circuits electrically connected in parallel such that they share a common drain region between their respective gate electrodes, and each has one source region.

Abstract: A LOCOS oxide film is provided in a main surface of a semiconductor substrate for isolating an element region from another element region. A channel cut layer formed of a P-type impurity is provided under the element region. A P.sup.+ impurity region having a concentration thicker than that of P-type impurity of channel cut layer is formed directly under a bird's beak portion of LOCOS oxide film in the main surface of semiconductor substrate. Therefore, an isolation breakdown voltage of an N-channel transistor region is increased.

Abstract: In a semiconductor device, a FET and an isolation are provided on a semiconductor substrate and a channel stop region is provided under the isolation. At least a region to which a high voltage is applied of a source region and a drain region of the FET is separated from the channel stop region, and a first buffer region doped with an impurity for adjusting the threshold level is provided therebetween. A region under a gate electrode and adjacent to the isolation serves as a second buffer region to which an impurity for adjusting the threshold level is doped. With the first buffer region, a depletion region at a boundary of the drain region and the channel stop region is ensured, obtaining a superior durability to high voltage of the source/drain region. With the second buffer region, leakage current between the source region and the drain region is prevented.

Abstract: A unique approach to suppressing latchup in CMOS structures is described. Atomic species that exhibit midgap levels in silicon and satisfy the criteria for localized action and electrical compatibility can be implanted to suppress the parasitic bipolar behavior Which causes latchup. Reduction of minority carrier lifetime can be achieved in critical parasitic bipolar regions that, by CMOS construction are outside the regions of active MOS devices. One way to accomplish this goal is to use the source/drain masks to locally implant the minority carrier lifetime reducer (MCLR) before the source/drain dopants are implanted. This permits the MCLR to be introduced at different depths or even to be different species, of the n and p-channel transistors. Another way to accomplish this goal requires that a blanket MCLR implant be done very early in the process, before isolation oxidation, gate oxidation or active threshold implants are done.

Abstract: A semiconductor memory device, e.g., a DRAM, which includes a P-type semiconductor substrate, a memory array each memory cell of which includes at least one N-channel MOS transistor, a CMOS peripheral circuit at least partially surrounding the memory array, the peripheral circuit including at least one P-channel MOS transistor formed in an N-type well region formed in the substrate, and at least one N-channel MOS transistor formed in the substrate outside of the N-type well region, and, a P-type minority carrier absorption semiconductor region formed in the substrate between the N-type well region and the memory array. The minority carrier absorption semiconductor region is preferably connected to a source of negative voltage, e.g., the substrate bias voltage, and a separate N-type region formed in the N-type well region is preferably connected to a source of positive voltage, e.g., the power supply voltage, Vdd, of the memory device.

Abstract: An n.sup.- epitaxial layer 4 is formed on the top face of a p type semiconductor substrate 1. A p.sup.+ buried layer 20 is formed by implanting ions in the region extending over the p type semiconductor substrate 1 and the n.sup.- epitaxial layer 4. A p.sup.+ channel stop is formed in the upper layer of the p.sup.+ buried layer 20 by ion implantation. A p well is formed extending from the upper layer of the p.sup.+ channel stop to the top face of the n.sup.- epitaxial layer. An n channel MOS type field effect transistor 200 is formed in the p well 22. It is possible to reliably isolate an element from an adjacent element thereto because of the structure.

Abstract: Soft error immunity of a storage cell is greatly increased by division of a storage node into at least two portions and location of those portions on opposite sides of an isolation structure, such as a well of a conductivity type opposite to that of the substrate in which transistors of the memory cell may also be formed. The isolation structure thus limits collection of charge to only one of the portions of the storage node and reduces charge collection efficiency to a level where a critical amount of charge cannot be collected in all but a statistically negligible number of cases when such charge is engendered by impingement by ionizing radiation, such as energetic alpha particles. The layout of the memory cell having this feature also advantageously provides a simplified topology for the formation of additional ports comprising word line access transistors and bit lines.

Abstract: Disclosed is a semiconductor device, such as a semiconductor memory device, having structure wherein invasion of minority carriers from the semiconductor substrate into components of the device, formed on the substrate, can be avoided. The semiconductor memory device can be an SRAM or DRAM, for example, and includes a memory array and peripheral circuit on a substrate. In one aspect of the present invention, a buried layer of the same conductivity type as that of the substrate, but with a higher impurity concentration than that of the substrate, is provided beneath at least one of the peripheral circuit and memory array. A further region can extend from the buried layer, for example, to the surface of the semiconductor substrate, the buried layer and further region in combination acting as a shield to prevent minority carriers from penetrating to the device elements.

Abstract: An IGFET has a non-single crystalline semiconductor layer formed on an insulating surface of a substrate. In a first embodiment, the semiconductor layer is intrinsic n- or p- type and the concentration of oxygen, carbon, or nitrogen in the layer is not higher than 5.times.10.sup.18 atoms/cm.sup.3, source and drain regions are formed in the semiconductor layer by selectively doping with an n-type or p-type impurity and selectively crystallizing the doped portion, and a channel region between the source and drain includes a hydrogen or halogen element. In another embodiment, the semiconductor layer is doped with a dangling bond neutralizer and a P-, I, or N- type channel region is formed in the layer. and a part of the channel region near the source-channel and drain-channel boundaries is selectively crystallized. Alternatively, the source and drain regions may be selectively crystallized without crystallizing the source-channel and drain-channel boundaries.

Abstract: This invention relates to a semiconductor integrated circuit device wherein guardring regions are formed between a first element region and a second element region so as to surround the first element region, wherein gate electrodes are provided to cross the guardring regions, wherein the guardring regions are continuously formed even directly below the gate electrodes, and wherein an insulator film directly below the gate electrodes is relatively thick.

Abstract: A monolithic complementary semiconductor device comprising n-type and p-type well regions separated by a dielectric isolation region extending from the surface into the substrate region. The well region includes a highly doped buried region which is located at the bottom of the well region and separates an active region in the wall from the substrate region. The isolation region is deeper than the buried region. The well-to-well isolation is enhanced by the combination of the buried region and the deep dielectric isolation region. Packing density and the high speed operation can also be improved.