Abstract: The present invention is directed to a method of forming conductive interconnections in an integrated circuit device. In one embodiment, the method comprises forming a dielectric stack comprised of multiple layers, and determining a thickness ratio of the layers of the stack. The method further comprises determining an etching process to be performed on the dielectric stack to define an opening for a conductive interconnection based upon the determined thickness ration, and performing the determined etch process on the dielectric stack.

Abstract: This invention discloses a DMOS power device supported on a substrate. The DOS power device includes a drain of a first conductivity type disposed at a bottom surface of the substrate. The DMOS power device further includes a gate disposed in a trench opened from a top surface of the substrate, the gate having a polysilicon layer filling the trenches padded by a double gate-oxide structure. The double gate-oxide structure includes a thick-oxide-layer covering walls of the trench below an upper portion of the trench and a thin-gate-oxide covering walls of the upper portion of the trench thus defining a champagne-glass shaped gate in the trench. The DMOS power device further includes a source region of the first conductivity type disposed in the substrate surrounding a top portion of the trench. The DMOS power device further includes a body region of a second conductivity type disposed in the substrate surrounding the trench and encompassing the source region.

Abstract: An ultra-large-scale integrated (ULSI) circuit includes MOSFETs which have different threshold voltages and yet have the same channel characteristics. The MOSFETs include gate structures with a polysilicon material. The polysilicon material is implanted with lower concentrations of germanium where lower threshold voltage MOSFETs are required. Over a range of 0-60% concentration of germanium, the threshold voltage can be varied by roughly 240 mV.

Abstract: Integrated circuit memory devices include a memory cell field effect transistor in an integrated circuit substrate, a conductive plug that electrically contacts the memory cell field effect transistor and a titanium nitride bit line that electrically contacts the conductive plug opposite the memory cell filed effect transistor. Titanium nitride also may be used to electrically contact field effect transistors in the peripheral region of the integrated circuit memory device. Titanium nitride can be used as a bit line metal instead of conventional tungsten, and as a conductive plug to contact both p+-type and n+-type source/drain regions in the peripheral region of the memory device. The titanium nitride conductive plugs and bit lines may be formed simultaneously.

Abstract: An integrated circuit containing separately optimized gate structures for n-channel and p-channel transistors is provided and formed. Original gate structures for both n-channel and p-channel transistors are patterned over appropriately-doped active regions of a semiconductor substrate. Protective dielectrics are formed over the semiconductor substrate to the same elevation level as the upper surfaces of the original gate structures, so that only the upper surfaces of the gate structures are exposed. A masking layer is used to cover the gate structures of either the p-channel or the n-channel transistors. The uncovered gate structures are removed, forming a trench within the protective dielectric in place of each removed gate structure. The trenches are refilled with a new gate structure which is preferably optimized for operation of the appropriate transistor type (n-channel or p-channel).

Abstract: An FET structure for utilization with a silicon-on-insulator semiconductor device structure. The structure includes a silicon-on-insulator substrate structure. Source and drain diffusion regions are provided on the silicon-on-insulator substrate. An FET body region is interconnected with the source and drain diffusion regions. A gate oxide region is arranged over at least a portion of the body region and the source and drain diffusion regions. A gate region is arranged over at least a portion of the gate oxide region. A diode is interconnected with and provides a conductive pathway between the gate region and the FET body region. The diode is electrically isolated from the FET source and drain regions and inversion channel by a high threshold FET region.

Abstract: An integrated semiconductor device includes a substrate having a buried shallow trench isolation structure and an epitaxial layer disposed over the substrate and the buried shallow trench isolation structure. The epitaxial layer includes a shallow trench isolation structure that extends over the buried shallow trench isolation structure in the substrate to substantially reduce leakage current in the substrate to prevent device latch-up.

Abstract: The provision of an isolation gate connecting unassociated active areas of adjacent transistors formed in a semiconductor substrate provides effective isolation of the adjacent transistors with no additional process steps required. The isolation gate is tied to a reference to ensure that a channel between the unassociated active areas is not formed, and effective isolation is provided. The adjacent transistors are cross coupled to form sense amplifiers for dynamic random access memory devices.

Abstract: A method and structure for an improved, vertically configured inverter array is provided. The inverter includes a buried gate contact coupling the body regions of a complementary pair of transistors. An electrical contact couples the second source/drain regions of the complementary pair of transistors. The transistors are formed in vertical pillars of single crystalline semiconductor material.

Abstract: A semiconductor device can reduce a leak current, and a manufacturing method can provide such a semiconductor device. A semiconductor device includes an isolating and insulating film formed on a main surface of a semiconductor substrate including a first conductivity type region, and also includes a field-effect transistor. The field-effect transistor includes a second conductivity type region neighboring to the isolating and insulating film, a gate electrode, a lower layer side wall film formed on a side surface of the gate electrode, an upper layer side wall film formed on the lower layer side wall film and containing a material different from that of the lower layer side wall film, and a high-melting-point metal silicide layer formed on the second conductivity type region.

Abstract: A semiconductor apparatus and method for producing shallow trench isolation. The method includes the steps providing a semiconductor substrate member fabricated having a thin barrier oxide layer on which are fabricated a plurality of spaced apart silicon nitride pads. The regions between the spaced apart nitride pads delineate U-shaped regions for forming shallow isolation trenches and are layered with silicon oxide and polysilicon. The U-shaped regions provide a buffer region of oxide and polysilicon material adjacent opposing silicon nitride pads that prevent erosion of the nitride during etch formation of the isolation trench. The polysilicon is further etched to form a wider, second U-shaped region having sloped sidewalls that provide opposing spacer-forming buffer material that facilitates forming a V-shaped isolation trench region into the semiconductor substrate member a predetermined depth without eroding the silicon nitride pads.

Abstract: An integrated circuit is presented. The integrated circuit may include a memory cell formed above an insulating base. The insulating base may either be arranged above a substrate or serve as a substrate itself. A transistor may be arranged above the memory cell. The transistor is preferably dielectrically isolated from the memory cell. In a preferred embodiment, a segmented substrate is arranged between the memory cell and transistor. The segmented substrate preferably includes a first conductive substrate layer arranged above and dielectrically spaced from the memory cell. A second conductive substrate layer may be formed above the first conductive substrate layer. The transistor may be arranged upon and within the second conductive substrate layer. Preferably, the segmented substrate further includes an intersubstrate dielectric layer interposed between the second conductive substrate layer and the first conductive substrate layer.

Abstract: A semiconductor device has a semiconductor substrate, an element isolation insulation film embedded in a trench formed in said semiconductor substrate in a state of protruding from a surface of said semiconductor substrate and a transistor having a gate electrode provided in an area surrounded by said element isolation insulation film on said semiconductor substrate, and containing a gate electrode deposited through a gate insulation film before embedding said element isolation insulation film and an upper edge corner of said element isolation insulation film is selectively recessed. In the thus structured semiconductor device, the upper edge corner of the element isolation insulation film is recessed before the patterning process of the gate electrode, thereby preventing such a situation that a part of the gate electrode remains unetched in the patterning process of the gate electrode.

Abstract: On the surface of a field oxide film (3 of FIG. 2e) formed on a substrate region where the effective thickness in the vertical direction of a substrate is diminished due to the presence of a crystal defect (2 of FIG. 1a), the field oxide film is etched by a predetermined thickness until a recess (4 of FIG. 2f) ascribable to the presence of the defect is exposed (step of FIG. 2f). A new oxide film then is formed in an amount corresponding to the above-mentioned thickness on the field oxide film (step of FIG. 3g) to diminish the depth of the recess ascribable to the presence of the defect. To provide a semiconductor device in which leakage between elements can be eliminated with a thin LOCOS oxide film thickness remaining unchanged.

Abstract: A quick, deep, clean two step trench process for an SOI/bonded wafer substrate 100 is disclosed. A first isotropic plasma etch using SF6 is made through an opening 40 in the photoresist layer on device layer 16. A second anisotropic plasma etch using SF6 and C12 stops on the isolation/bond oxide layer 14. The bottom of the trench 60 is overetched to form cavities 50 on the isolation/bond oxide layer 14 without removing a substantial portion of that layer.

Abstract: High voltage and low voltage devices are provided on a common semiconductor substrate. An integrated semiconductor circuit includes a semiconductor substrate of a first conductivity type. Well regions of a first conductivity type and well regions of a second conductivity type are formed in the substrate. Low voltage devices are formed in well regions of the first conductivity type. A high voltage device includes source/drain regions of the second conductivity type formed, respectively, in well regions of the second conductivity type, an oxide region disposed on a surface of the substrate located above a region of the substrate that serves as a channel for the high voltage device, and a gate region disposed on the oxide region.

Abstract: A method of forming integrated isolation regions and active regions includes first forming a plurality of dielectric layers upon a semiconductor substrate. Then, a patterned mask is applied to define portions of the dielectric layers that will remain to form isolation regions and to define portions of the dielectric layers that will be removed in an etch step to create voids to the surface of the semiconductor substrate. Subsequently, epitaxially growth is employed to form active regions within the voids that were previously formed. Transistors are then formed in and on the active regions and are subsequently interconnected to form an integrated circuit.

Abstract: A trench DMOS device has a gate insulating layer on the bottom and sidewalls of the trench. The upper edges of the trench have an impurity injection region and are rounded. In addition, a first conductive layer is formed on the gate insulating layer, and a second conductive layer is formed on the first conductive layer and filled in the trench. The second conductive layer has different crystallization from the first conductive layer. As such the first conductive layer acts as a buffer between the gate insulating layer and the filled in second conductive layer. A method for fabricating a trench DMOS device includes the steps of forming an epitaxial layer on a semiconductor substrate. Then an impurity is injected into the epitaxial layer to form an impurity injection region. Then a trench is formed in the semiconductor substrate passing through the impurity injection region. Then a dry etching process is used to round the upper edges of the trench.

Abstract: A method for isolating semiconductor devices comprising providing a semiconductor substrate. The semiconductor substrate includes laterally displaced source/drain regions and channel regions. First and second laterally displaced MOS transistors are formed partially within the semiconductor substrate. The first and second transistors have a common source/drain region. An isolation trench is formed through the common source/drain region and the trench is filled with a trench dielectric material such that the common source/drain region is divided into electrically isolated first and second source/drain regions whereby the first transistor is electrically isolated from the second transistor.

Abstract: In a semiconductor device and a method of manufacturing the same, a dummy region which can suppress occurrence of a parasitic capacity can be provided for reducing a difference in level without increasing manufacturing steps in number. A semiconductor substrate is provided at its main surface with an isolation region formed by a trench, and a dummy region leaving the main surface is formed in the isolation region for the purpose of reducing an influence by the difference in level in a later step. The dummy region includes p- and n-type impurity regions each extending a predetermined depth from the surface. Since a pn junction occurs at the bottom of the impurity region, a depletion layer spreads in the pn junction, and thereby reduces a parasitic capacity between the dummy region and a conductive interconnection located in a crossing direction at a higher position.

Abstract: An SOI chip having an isolation barrier. The SOI chip includes a substrate, an oxide layer deposited on the substrate, and a silicon layer deposited on the oxide layer. A gate is deposited above the silicon layer. A first metal contact is deposited above the gate to form an electrical contact with the gate. Second and third metal contacts are deposited to form electrical contacts with the silicon layer. The isolation barrier extends through the silicon layer and the oxide layer, and partially into the substrate, to block impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier. The isolation barrier surrounds the gate, the first metal contact, the second metal contact, and the third metal contact--which define an active chip area inside the isolation barrier. A method of manufacturing the SOI chip is also disclosed.

Abstract: In a CMOS circuit including a source diffusion layer and a well region which are at the same potential, a P.sup.+ -type source diffusion layer and an N.sup.+ -type substrate diffusion layer are formed in a portion corresponding to a source region in a surface area of an N-type well region. A source contact is formed on the source and substrate diffusion layers through a salicide layer to connect the diffusion layers to their upper wiring layer. Since, therefore, the source contact can be arranged closer to a P-type well region, the layout area can be reduced.

Abstract: A CMOS SRAM cell includes a substrate divided by a well trench into an n well region and a p well region, first and second active regions each having a V shape, formed symmetrical relative to each other, and having the well trench in between, third and fourth active regions formed symmetrically relative to each other and offset from the second active region, first and second gate lines each crossing the first active region, the well trench, and the second active region, and a third gate line crossing the third and fourth active regions.

Abstract: A semiconductor structure comprises first gate conductors which wrap around N-wells of buried-channel P-type metal oxide semiconductor field effect transistors and second gate conductors which do not wrap around P-wells of surface-channel N-type metal oxide semiconductor field effect transistors and a method of manufacturing the same comprises forming insulators adjacent each of the N-wells and the P-wells, protecting the N-wells with a patterned mask, forming first divots in areas of the insulators adjacent the N-wells and forming second divots in areas of the insulators adjacent P-wells, wherein the first divots have a greater depth than the second divots.

Abstract: Silicon conductive vias and pedestals are disclosed for use in microwave integrated circuits. The pedestals are isolated from a ground plane on the bottom surface by glass, while the vias are used to make electrical contact to ground. Electrical circuit elements in the top surface of the integrated circuit are selectively grounded or isolated by the choice of connection to a via or pedestal, respectively.

Abstract: An isolation structure is provided that includes a substrate (10), a refill material such as a refill oxide (22), a gate dielectric such as a gate oxide layer (24), and a gate conductor layer such a polysilicon gate layer (26). The substrate (10) has an active region (12), an active region (14), and a trench region provided between the active region (12) and the active region (14). The active region (14) includes a top corner (32) that is provided where an upper surface of the active region (14) and the trench wall of the trench region that is adjacent to the active region (14) meet. The refill oxide (22) is positioned within the trench region and extends to cover at least a portion of the top corner. The gate oxide layer (24) is provided on the upper surface of the active region (14). The polysilicon gate layer (26) is provided on an upper surface of the gate oxide layer (24).

Abstract: A photoresist pattern is formed on a field oxide film and an element forming region across the field oxide film and the element forming region such that a portion of a surface of the field oxide film and a portion of a surface of a silicon epitaxial layer are continuously exposed. The photoresist pattern is used as a mask to inject boron ions into the silicon epitaxial layer and heat treatment is performed thereon to form an external base containing the relatively significant crystal defect present in the silicon epitaxial layer in the vicinity of the field oxide film. Thus, a semiconductor device can be obtained including a bipolar transistor which provides improved breakdown voltage between the collector and the base and contemplates reduction of current leakage.

Abstract: According to the present invention, a semiconductor device, and method for producing the same, is provided comprising: a resistance component formed in a component active region enclosed by a component separating-insulating layer on a semiconductor base; one pair of first diffusion layers containing a high concentration of impurities which are provided at both ends of the component active region; silicide layer adhering to a first diffusion layer; second diffusion layer containing a low concentration of impurities which is provided in the component active region between the pair of first diffusion layers; wherein a first diffusion layer and silicide layer comprise the terminal areas of the resistance component, and the second diffusion layer comprises a resistance member area of the resistance component.

Abstract: A circuit and method for an improved inverter is provided. The present invention capitalizes on opposing sidewalls and adjacent conductive sidewall members to conserve available surface space on the semiconductor chips. Additionally, the gate and body of the transistors are biased to modify the threshold voltage of the transistor (V.sub.t). The conductive sidewall member configuration conserves surface space and achieves a higher density of surface structures per chip. This design provides fast switching capability for low power battery operated CMOS circuits and systems. The transistor structure offers performance advantages from both metal-oxide semiconductor (MOS) and bipolar junction transistor (BJT) designs. The devices can be used in a variety of applications, digital and analog, wherever a more compact structure with low power consumption and fast response time is needed.

Abstract: A structure for increasing the threshold voltage of a corner device, particularly for shallow trench isolation having narrow devices. An FET comprises a substrate having a channel formed therein under a gate between spaced source and drain regions. A trench isolation region is formed in the substrate around the transistor and on opposite sides of the channel to isolate the transistor from other devices formed in the substrate, with the trench isolation region forming first and second junction corner devices with opposite sides of the channel. A first dielectric layer is formed under the gate and over the channel of the field effect transistor to form a gate insulator for the transistor.

Abstract: High density, multi-metal layer semiconductor devices are formed with self-aligned vias and reliable interconnection patterns employing photolithography without the use of a photomask. Embodiments include modulating the amount of energy reflected into an overlying photoresist layer from underlying components to effect differential exposure of the photoresist layer.

Abstract: A semiconductor apparatus and method for making the same is disclosed herein in which the semiconductor apparatus includes a first active device formed in a mesa region of semiconductor material formed on one or more sidewalls of an isolation region, and a conductive path which extends from the active device in a linear direction of the mesa. An embodiment is disclosed in which a plurality of active devices are formed in the mesa region and electrically connected thereby.

Abstract: A semiconductor device, including a circuit configuration formed on a semiconductor substrate, comprises: a boosting circuit for boosting an external power supply voltage to a plus voltage and a minus voltage; and a detecting circuit having a resistor formed of an impurity diffused layer so that the plus voltage and the minus voltage boosted by the boosting circuit are respectively connected to the resistor, to detect a potential at a prescribed point of said resistor so as to verify whether or not the boosting circuit has generated a desired potential.

Abstract: Methods of forming semiconductor-on-insulator field effect transistors include the steps of forming an insulated trench containing a semiconductor region therein and an insulating region mesa at a bottom of the trench, so that the semiconductor region has relatively thick regions adjacent the sidewalls of the trench and has a relatively thin region above the mesa. Dopants can then be added to the thick regions to form low resistance source and drain regions on opposite sides of the thin region which acts as the channel region. Because the channel region is thin, low junction capacitance can also be achieved. An insulated gate electrode can also be formed on the face of the semiconductor region, above the channel region, and then source and drain contacts can be formed to the source and drain regions to complete the device.

Abstract: A shallow trench isolation structure and a method for forming the same for use with non-volatile memory devices is provided so as to maintain sufficient data retention thereof. An epitaxial layer is formed on a top surface of a semiconductor substrate. A barrier oxide layer is formed on a top surface of the epitaxial layer. A nitride layer is deposited on a top surface of the barrier oxide layer. Trenches are formed through the epitaxial layer and the barrier oxide layer to a depth greater than 4000 .ANG. below the surface of the epitaxial layer so as to create isolation regions in order to electrically isolate active regions in the epitaxial layer. A liner oxide is formed on sidewalls and bottom of the trenches to a thickness between 750 .ANG. to 1500 .ANG.. As a result, leakage current in the sidewalls are prevented due to less thinning of the liner oxide layer by subsequent fabrication process steps.

Abstract: An oxidation layer 44 for masking is formed on a PNP type transistor formation region 46a together with a field oxidation layer 42 for device separation. The oxidation layer 44 for masking is formed so as to cover an upper part of an active base formation region 52a located between the emitter/collector formation region 50a. The upper part of the active base formation region 52a which is not possible to adjust impurity concentration at processes carried out later is covered with the oxidation layer 44 for masking being formed relatively thick when boron B is implanted into a PMOS type transistor formation region 48a as channel ion. So that, boron is not implanted ionically to the active base formation region 52a. Therefore, it is not necessary to carry out masking process using photo resist layer in prior to boron implantation process.

Abstract: A semiconductor device array having silicon device islands isolated from the substrate by an insulator. High array density is achieved by forming source and drain interconnects in the space between the islands. Also disclosed are processes for forming and programming such arrays.

Abstract: A shallow junction MOS transistor comprising a semiconductor substrate having an upper region that includes a first and a second lightly doped region laterally displaced on either side of the channel region. The first and second lightly doped regions extend to a junction depth below the upper surface of the semiconductor substrate. A first and a second lightly doped impurity distribution are located within the first and second source/drain regions of the semiconductor substrate. The shallow junction transistor further includes a gate dielectric formed on an upper surface of the channel region of the semiconductor substrate. A conductive gate that includes a first and a second sidewall is formed on the gate dielectric. A gate insulator is formed in contact with the first and second sidewalls of the conductive gate. First and second source/drain structures are formed above the upper surface of the semiconductor substrate.

Abstract: A high voltage device. A first-type semiconductor substrate having at least a gate formed thereon is provided. The high voltage comprises a second-type first diffusion region in the semiconductor region, a second-type second diffusion region within the first diffusion region, a second-type third diffusion region under the second diffusion region, a field oxide layer on a part of the second diffusion region, and a first-type source/drain region under a surface between the field oxide layer and the gate.

Abstract: A wet etching process for establishing isolation grooves in a flash memory core wafer includes depositing nitride and/or oxide layers on a silicon substrate of the wafer, depositing a photoresist layer thereon, and then exposing predetermined portions of the photoresist layer to ultraviolet light to establish a desired groove pattern in the photoresist layer. A dry etching process is then used to remove the nitride and/or oxide layers beneath the groove pattern of the photoresist layer to thereby expose portions of the substrate. Next, the wafer is disposed in a wet etching solution such as potassium hydroxide to form grooves in the exposed portions of the silicon substrate. The wafer is oriented and disposed in the bath as appropriate for forming V-shaped grooves, such that after etching, the angled walls of the grooves can be easily exposed to a dopant beam directly above the wafer, without having to tilt the wafer or beam source. Thereby, the walls of the grooves are easily implanted with dopant.

Abstract: A method is provided for a planar surface of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A conductive layer is formed over a substrate. A silicon nitride layer is formed over the conductive layer. A photoresist layer is then formed and patterned over the silicon nitride layer. The silicon nitride layer and the conductive layer are etched to form an opening exposing a portion of the substrate. The photoresist layer is then removed. The exposed substrate and a portion of the conductive layer exposed along the sidewalls in the opening are oxidized. An planarizing insulating layer such as spin-on-glass is formed over the silicon nitride layer and in the opening. The insulating layer is etched back to expose the silicon nitride wherein an upper surface of the insulating layer is level with an upper surface of the conductive layer. The silicon nitride layer is then removed. A planar silicide layer is then formed over the conductive layer.

Abstract: A semiconductor apparatus formed on a semiconductor substrate includes a first active region in the substrate, and a second active region adjacent to the surface of the substrate separated from the first active region by a channel region. A gate oxide region may overlie at least a portion of the first and second active regions. The apparatus further includes a gate positioned over the channel region and having a first end and a second end respectively associated with the first and second active regions. The gate includes a first low conductive region and a second low conduction region at said first and second ends, respectively.A method for making the transistor structure of the present invention is also provided.

Abstract: A semiconductor device includes a semiconductor substrate in which a trench for element isolation is formed, and an element isolation oxide film buried into the trench in such a manner that the element isolation oxide film is projected from the surface of the semiconductor substrate. The element isolation oxide film which is an element isolation insulating film for defining an element forming region on the semiconductor substrate has a projection portion above the surface of the semiconductor substrate. The projection portion has the width wider than that of the trench. The projection portion and a contact portion made in contact with the semiconductor substrate within the trench are made of thermal oxide films, and a portion other than the projection portion and the contact portion is made of a CVD dioxide film.

Abstract: The semiconductor device comprises a semiconductor substrate having an element region, an element isolation film formed on the semiconductor substrate so as to surround the element region, a gate portion crossing the element region and extending over the semiconductor substrate, the gate portion comprising at least a gate insulation film formed on the semiconcuctor substrate and a gate electrode formed on the gate insulation film, and source/drain regions formed on the surface of the element regions on both sides of the gate portion, wherein an upper surface of the element isolation film is formed in substantially the same plane as an upper surface of the gate portion.

Abstract: An integrated circuit transistor and a method for making the same are provided. The transistor is resistant to junction shorts due to the overetch of local interconnect trenches. The transistor includes a source/drain region with a first junction and a second junction that is located deeper than the first junction in the portion of the active area susceptible to the overetch junction short phenomena. The second junction is established by ion implantation through a mask that is patterned to create an opening corresponding to the intersection of the layouts of the active area and the local interconnect trench. Using this method, the second junction is only established where needed to prevent shorting and does not impede transistor performance.

Abstract: A semiconductor fabrication process in which a transistor trench and an isolation trench are simultaneously formed in a semiconductor substrate. The transistor trench is laterally displaced from the isolation trench. Thereafter the isolation trench is filled with an isolation material and a gate dielectric is formed on the floor of the transistor trench. Next, a conductive gate is formed on the gate dielectric and a source/drain impurity distribution is introduced into a source region and a drain region of the semiconductor substrate. The drain region and the source region are laterally disposed on either side of the transistor trench. In a presently preferred embodiment, the semiconductor substrate comprises a substantially single crystal p+ silicon bulk and a p- epitaxial layer formed upon the p+ silicon bulk.

Abstract: An insulating trench isolation structure is formed in a semiconductor substrate with a spacer overlying the trench edge to prevent oxide loss during subsequent etching, thereby preventing junction leakage, particulary upon silicidation. Embodiments include providing a step in the trench fill and forming the nitride spacer during gate electrode sidewall spacer formation. The protective nitride spacer etches more slowly than oxide and, hence, remains after subsequent oxide etching and cleaning.

Abstract: A semiconductor MOSFET device is formed on a silicon substrate which includes trenches filled with Shallow Trench Isolation dielectric trench fill structures and extending above the surface of the substrate. The trench fill structures have protruding sidewalls with channel regions in the substrate having corner regions adjacent to the trench fill structures. The channel regions are between and adjacent to the STI trench fill structures doped with one concentration of dopant in the centers of the channel regions with a higher concentration of dopant in the corner regions. The dopant concentration differential provides a substantially equal concentration of electrons in the centers and at the corner regions of the channel regions.

Abstract: A semiconductor substrate having a shallow trench isolation (STI) structure and a method of manufacturing the same are provided, i.e., an isolation substrate in which grooves are selectively formed at predetermined locations of the semiconductor substrate and oxide films using organic silicon source as material are buried in the grooves as buried oxide films. The present invention is characterized in that the buried oxide films are annealed at a predetermined temperature within the range of 1100 to 1350.degree. C. before or after planarization of the semiconductor substrate such that ring structures of more than 5-fold ring and ring structures of less than 4-fold ring are formed at predetermined rates in the buried oxide films. The above annealing allows stress of the oxide film buried in the grooves to be relaxed. Hence, the generation of dislocation is suppressed.

Abstract: A shallow trench isolated FET LDD structure that has a low probability of short circuiting at the silicon to trench interface or between the source or drain and the gate (because of a titanium silicide bridge) is described. It is based on an isolation trench having a top portion with vertical sides and a lower portion with sloping sides. With the filled trench in place, along with a polysilicon gate and gate oxide, the thinner, lightly doped, N type layer is formed using ion implantation. Spacers are then formed on the gate but, prior to the second ion implant step, a few hundred Angstroms of silicon is selectively removed from the surface. This causes the trench filler material to extend above the wafer surface and the spacers to extend above the gate. A deeper, more strongly N-type, layer is then formed in the usual way, followed by the standard SALICIDE process for making contact to source, gate, and drain.