Abstract: A conductor crossing a trench around an electrical component is electrically connected to an isolated intermediate conducting region in order to move the field strength concentrations out of the electrical component and into the intermediate conducting region. This prevents avalanche breakdown from occurring in the electrical component.

Abstract: Prevents deterioration of the element characteristics of the gate voltage tolerance and the like which is caused by the metallic contaminants that are sealed in the element forming region at the time of applying a trench separator in a SOI substrate. Polysilicon 12 is formed on the side walls of the trench 5, and the metallic contaminants within the element forming region are collected in this polysilicon 12.

Abstract: Methods for fabricating a semiconductor device suitable for increasing process tolerance of the device are disclosed. One method includes the steps of sequentially forming an insulating layer, a planarization layer, and a nitride layer over cell transistors formed on a substrate; patterning the nitride layer to define first contact holes; forming polysilicon sidewall spacers on the sides of the patterned nitride layer; removing portions of the planarization layer and the insulating layer using the patterned nitride layer and the polysilicon sidewall spacers, so as to define second contact holes; and forming pad polysilicon layers in the second contact holes, so as to expose portions of the patterned nitride layer.

Abstract: A semiconductor integrated circuit with a transistor formed within an active area defined by side-walls of a shallow trench isolation region, and method of fabrication thereof, is described. A gate electrode is formed over a portion of the active area and LDD regions formed that are self-aligned to both the gate electrode and the trench side-walls. A dielectric spacer is formed adjacent the gate electrode and extending to the trench side-walls. In this manner, the spacers essentially cover the LDD regions. Source and drain regions are formed that are adjacent the trench side-walls wherein the spacer serves to protect at least a portion of the LDD regions to maintain a spacing of the S/D regions from the gate electrode edge. In this manner an advantageously lowered E.sub.M provided by LDD regions is maintained. In some embodiments of the present invention, S/D regions are formed by implantation through the trench side-walls.

Abstract: In a MOSFET having a polysilicon gate electrode, the polysilicon layer of the gate electrode is nonuniformly doped with an impurity for the same type of conductivity as the source and drain regions such that the effective impurity concentration gradually and continuously decreases from a top section toward a bottom section adjacent to the gate oxide film and becomes minimum in the bottom section. When a high voltage is applied between the drain and the gate, a depletion layer is created in the bottom section of the polysilicon layer, whereby the electric field on the gate oxide film is reduced. Accordingly, the thickness of the gate oxide film can be reduced for high-speed operation. Besides, this MOSFET is useful in a high-voltage interface for a MOS circuit operated at a low supply voltage. The doping of the polysilicon layer is accomplished by ion implantation. It is suitable to employ a lightly doped drain (LDD) structure in this MOSFET.

Abstract: In an NPN transistor of this invention having a trench isolation structure, for example, an N.sup.+ -type buried layer and an N.sup.- -type epitaxial layer are stacked on an element forming region of a P.sup.+ -type substrate, and a trench having polysilicon filled therein is formed in a portion adjacent to the element forming region. Further, a field oxide film is formed to extend from the trench having polysilicon filled therein over to the adjacent element isolation region without extending into the element forming region. Thus, a distance from the front end portion of the field oxide film on the element forming region side to the trench is reduced to reduce the element area. Therefore, the parasitic capacitance can be reduced and the power consumption of a circuit can be reduced.

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 sensor element provided with a silicon substrate having a semiconductor circuit, a sensing-element portion formed on the silicon substrate and connected to the semiconductor circuit, and a cavity portion formed by removing a silicon substrate portion below the sensing-element portion, in which a removal resistance region having resistance against substrate removal is provided in the silicon substrate between the semiconductor circuit and the cavity portion.

Abstract: A trench refill for a semiconductor device is undertaken by depositing polycrystalline Ge or Ge.sub.x Si.sub.1-x alloy at temperatures as low as 500.degree. C. The structure is then oxidized at for example 700.degree. C. to obtain a cap oxide on the trench refill. This method causes avoidance of (1) void formation, (2) facet formation, and (3) necessity of a second insulator deposition and planarization, meanwhile achieving all these advantages at a low thermal budget.

Abstract: A contact region for a trench in a semiconductor device and a method for electrically contacting the conductive material in a trench that is too narrow for conventional electrical contacts may include a contact region in which the trench is divided into two or more trench sections, each section having the same narrow width as the undivided trench. The two or more trench sections are separated by one or more islands that are isolated from the semiconductor device. An aperture through the material above the contact region provides access for electrically contacting the conductive material in the trench sections.

Abstract: A field effect transistor relative to a semiconductor substrate, where the transistor has a gate which defines a resultant lateral expanse of semiconductive material therebeneath for provision of a transistor channel region, includes a) providing a conductive gate layer over a semiconductor substrate; b) patterning the conductive gate layer into a first gate block, the first gate block having a first lateral expanse which is greater than the resultant lateral expanse; c) providing an insulating dielectric layer over the first gate block; d) providing a patterned layer of photoresist over the first gate block and the insulating dielectric layer, the patterned photoresist comprising a photoresist block positioned over and within the first lateral expanse of the first gate block; e) with the patterned photoresist in place, etching the insulating dielectric layer selectively relative to the first gate block; f) after etching the insulating dielectric layer and with the patterned photoresist in place, etching the

Abstract: A manufacturing method of semiconductor devices and semiconductor devices isolated by a trench portion. The trench portion is refilled with a Si epitaxial growth layer. The trench has a first insulating layer on its side wall and a second insulating layer formed by the oxidation in the self-alignment manner, as a cap layer, on the top portion of the trench. A semiconductor device formed on the substrate is isolated by the trench. The excessive leakage currents created by the stress between the substrate and the Si epitaxial layer are decreased. The concentration of the field effect at the corner portion of the trench is suppressed by the cap layer.The refilling step can be also made to a trench having the wider opening and another trench having the narrower opening simultaneously and uniformly.

Abstract: Trenches 72 are formed in substrate 17 late in the fabrication process. In order to avoid trench sidewall stresses that cause defects in the substrate monocrystalline lattice, the trenches are filled after a final thick thermal oxide layer, such as a LOCOS layer 25, is grown. The trenches 72 are also filled after a final deep diffusion, i.e. a diffusion in excess of one micron.

Abstract: A semiconductor device, polysilicon-contacted trench isolation- structure that provides improved electrical isolation stability, a method of operating a polysilicon-contacted trench isolated semiconductor device, and a process for manufacturing a polysilicon-contacted trench isolation structure. The trench isolation structure includes an isolation trench formed in a semiconductor substrate. The isolation trench has a layer of trench lining oxide, a layer of trench lining silicon nitride and a trench fill polysilicon (poly 1) layer. Exposed lateral surfaces of the poly 1, which extend above the trench lining silicon nitride, are contacted to another layer of polysilicon (poly 2). The method of operation includes applying a bias voltage to the trench fill poly 1 layer via poly 2. The process for manufacture includes etching an isolation trench that extends through a layer of field oxide and into a semiconductor substrate.

Abstract: A fabrication process for dielectrically isolated high frequency complementary analog bipolar and CMOS transistors. Polysilicon extrinsic bases, polysilicon emitters with sidewall spacers formed after intrinsic base formation provides high current gain, large emitter-to-base breakdown voltage, large Early voltage, and high cutoff frequency.

Abstract: A method for preparing an SRAM or DRAM structure on a substrate with an oppositely doped well therein, a field oxide region extending above and between the well and the substrate, first and second N-MOS transistors on the silicon substrate, and a P-MOS transistor on the silicon well. The source and drain regions of each of the P-MOS transistor and the first and second N-MOS transistors each have a polysilicon plug making contact therewith. Each polysilicon plug is isolated one from another by nitride spacers, has the same doping as the region with which it makes contact, and is self-aligned to the nitride spacers lining the passage of the polysilicon plugs to their respective contacts on either the silicon substrate or the silicon well. The self-aligned nature of the polysilicon plugs is due to the nitride spacers formed by etchant selectivities and photoresist masks.

Abstract: An LSI semiconductor device having a device isolation structure and a method of fabricating the isolation structure are presented. The device is a buried-type field-shielding device which is fabricated in non-active regions of the LSI circuit, and includes field-shield insulator film formed on the interior walls of trench cavities formed on the substrate and the field-shield electrodes buried within the trench cavity. Unlike the conventional buried-type isolation devices, the top surface of present isolation structure is level with the upper surface of the substrate. Therefore, this device structure utilizes the interior space of the substrate rather than the surface area of the substrate as in the conventional field-shield isolation structure.

Abstract: A semiconductor device having the base and collector surrounded by a continuous tungsten filled slot as ground plane. The portion of the tungsten filled slot over the buried layer extends beyond the surface of the buried layer and the portion of the tungsten filled slot not over the buried layer extends beyond the interface between the epitaxial layer and the substrate.

Abstract: Semiconductor device chips having a first layer of semiconductor material, a second layer of a semiconductor material and an insulating layer disposed therebetween. The first layer of semiconductor material has doped semiconductor regions disposed therein, and the second layer of semiconductor material has a power device disposed therein. The power device is disposed beneath the doped semiconductor region of the first layer. Trenches may be located within the first layer of semiconductor material to electrically isolate different areas having doped semiconductor regions. The insulating layer is typically formed from an oxide.

Abstract: Ordinary anisotropic etching is performed up to a depth (d1) while anisotropic etching is performed to form an inward taper from the depth (d1) by changing etching conditions such as components in a vapor phase and the temperature of a silicon substrate (1), thereby forming a groove (20). Thereafter silicon is epitaxially grown in the groove (20), thereby forming an epitaxial silicon layer (4). An NMOS transistor is formed on an upper layer part of the epitaxial silicon layer (4). At this time, the taper of the groove (20) is located under a part of an n.sup.+ layer (8) forming the NMOS transistor. Thus, a method of fabricating a semiconductor device capable of performing element isolation with neither halation nor formation of bird's beak in fabrication while minimizing a leakage current flowing across elements is obtained.

Abstract: An integrated circuit comprises a plurality of interconnected semiconductor devices, at least one the interconnected devices being dielectrically isolated from the substrate, and at least one other of the interconnected devices being junction isolated from the substrate. In a preferred embodiment, at least one of the junction isolated devices comprises an ESD protection circuit. The ESD protection circuit, which preferably includes a zener diode and more preferably further includes a bipolar transistor, a diode, and a resistor, is formed in a trench-isolated island comprising a semiconductor layer of a conductivity type opposite to that of the substrate. A heavily doped buried semiconductor region of the same conductivity type as the substrate is formed in the island semiconductor layer adjacent to the substrate.

Abstract: A semiconductor IC comprising a supporting substrate; a first buried insulator film formed partially on the supporting substrate; a second buried insulator film thinner than the first buried insulator film formed partially on the supporting substrate; a plurality of island-shaped semiconductor layers formed on the first and second buried insulator films, respectively; and dielectric isolation regions formed between the plurality of island-shaped semiconductor layers. A surge protection circuit is formed in the island-shaped semiconductor layer formed on the second buried insulator film and also an internal circuit is formed in other island-shaped semiconductor layers formed on the first buried insulator film. Surface wirings are disposed to interconnect the surge protection circuit and the internal circuit.

Abstract: An integrated high-performance decoupling capacitor, formed on a semiconductor chip, using the substrate of the chip itself in conjunction with a metallic deposit formed on the presently unused chip back surface and electrically connected to the active chip circuit to result in a significant and very effective decoupling capacitor in close proximity to the active circuit on the chip requiring such decoupling capacitance.Specifically the present invention achieves this desirable result by providing a dielectric layer on the unused backside of the chip and forming a metal deposit on the formed backside dielectric layer and an electrical connection, between the metallic deposit and the active chip circuit via a through hole in the chip.

Abstract: A semiconductor device and method having a low-permittivity material between closely-spaced leads in order to decrease unwanted capacitance, while having a more structurally strong dielectric between widely-spaced leads where capacitance is not as critical. Metal layer 14 is deposited on a substrate 12 of a semiconductor wafer 10, where the metal layer 14 has a first portion 15 and a second portion 17. Widely-spaced leads 16 are formed in the first portion 15 of the metal layer 14, and a first structural dielectric layer 26 is deposited on at least the widely-spaced leads. Closely-spaced leads 18 are formed in the second portion 17 of the metal layer 14, and low-permittivity material 34 is deposited between closely-spaced leads 18. A second structural dielectric layer 36 is deposited on at least low-permittivity material 34 and closely-spaced leads 18.

Abstract: An integrated circuit structure and a method of fabrication thereof are provided. In particular, fully planarized, trench isolated semiconductor regions, e.g. comprising doped polysilicon, are provided in an integrated circuit substrate. These polysilicon regions have a smooth surface, substantially coplanar with the substrate surface, provided by chemical mechanical polishing. The near zero topography substrate provides for formation thereon of integrated circuit structures including e.g. capacitors, resistors, thin film capacitors, and interconnects, in the polysilicon trench regions at the same process level as devices formed in the semiconductor substrate. Thus a simple and flexible process for formation of improved device structures is provided, compatible with known Bipolar, CMOS and Bipolar-CMOS processes.

Abstract: The preferred embodiment of the present invention overcomes the limitations of the prior art and provides a device and method to increase the latch-up immunity of CMOS devices by reducing the mobility of carriers between the devices. The preferred embodiment uses an implant formed beneath trench isolation between n-channel and p-channel devices. This implant preferably comprises relatively large/heavy elements implanted into the wafer beneath the trench isolation. The implant elements reduce the mobility of the charge carriers. This increases the latch-up holding voltage and thus reduces the likelihood of latch-up. The implants can be formed without the need for additional photolithography masks.

Abstract: A semiconductor device having the SOI structure is provided, which enables to reduce the size of components compared with the conventional semiconductor devices. The device contains a first insulator film formed on a semiconductor substrate, and semiconductor islands formed on the first insulator film. Each of the islands has an electronic component. The device further contains semiconductor sidewalls formed to surround the respective islands. The sidewalls are contacted with outer sides of the corresponding islands. Electrodes are formed outside the islands to be contacted with the corresponding sidewalls. A second insulator film is formed on the exposed first insulator film from the islands to laterally isolate the respective islands and the corresponding sidewalls from each other. The electronic components are electrically connected to the respective electrodes through the corresponding sidewalls.

Abstract: An FET isolated on either side by a trench. The FET has a dielectric layer in the isolating trench along at least one side. The dielectric layer which may be an ONO layer has an oxidation catalyst diffused into it. The oxidation catalyst may be potassium. A gate oxide along the side of the FET in close proximity to the ONO layer is thicker than gate oxide between both sides.

Abstract: A method of forming field oxide during the manufacture of a semiconductor device comprises the steps of providing a semiconductor wafer having a plurality of recesses or trenches therein. A layer of texturized polycrystalline silicon is formed within the recesses, which is subsequently oxidized to form field oxide. The instant method reduces stress imparted to the die as the texturized polycrystalline silicon has voids or holes which absorb the expanding volume as the silicon is oxidized to form field oxide.

Abstract: In a microelectronic device formed on a substrate 12, a pair of trenches 30, 36 connected at their intersection by trench 54 which is disposed at an obtuse angle with respect to each of the pair of trenches 30 and 36.

Abstract: A semiconductor device has a semiconductor substrate having a groove, and a semiconductor element formed in a surface region of the semiconductor substrate. A substance having a thermal expansion coefficient different from the semiconductor substrate is embedded in at least a portion of the groove, a crystal defect is generated from the region near the bottom of the groove in the semiconductor substrate, thereby alleviating stress and strain in other regions of the semiconductor substrate, such that such regions cannot generate crystal defects in a region necessary for a circuit operation of the semiconductor element of the surface region.

Abstract: The opening width of an element isolating trench is Wa'. The opening width of a substrate potential setting trench is Wb'. When the maximum film thickness of a polysilicon film lying on the side wall of each of the trenches is set to t, the opening width Wa' of the element isolating trench and the opening width Wb' of the substrate potential setting trench satisfies a condition that (Wa'-2t)<(Wb'-2t) and Wa'>2t. A silicon oxide film covers the entire portion of the internal surface of the element isolating trench and covers the internal surface of the substrate potential setting trench except the bottom portion thereof. Therefore, the polysilicon film in the element isolating trench is set in the electrically floating state and the polysilicon film in the substrate potential setting trench is connected to the semiconductor substrate.

Abstract: A fabrication process for dielectrically isolated high frequency complementary analog bipolar and CMOS transistors. Polysilicon extrinsic bases, polysilicon emitters with sidewall spacers formed after intrinsic base formation provides high current gain, large emitter-to-base breakdown voltage, large Early voltage, and high cutoff frequency.

Abstract: A semiconductor device which can compatibly achieve the improvement of the withstand voltage and the integration degree. A PN junction between a buried collector region 3 and a collector withstand voltage region 4 is subjected to reverse bias, and a depletion layer in the PN junction reaches a side dielectric isolation region 9a which dielectrically isolates the side of the collector withstand voltage region 4. A circumferential semiconductor region 14 which is in adjacency to the collector withstand voltage with the side dielectric isolation region 9a therebetween has an electric potential that is approximate to that at a base region 5 rather than that at the buried collector region 3. As a result, the depletion layer is subjected to the effect of low electric potential from both the base region 5 and the circumferential semiconductor region 14.

Abstract: Disclosed is an integrated circuit having at least two active components, such as transistors, having the following features:a highly conductive substrate is provided which is connected to one pole of a voltage supply source,a semiconductor layer, which is electrically isolated from the substrate and divided into individual sections by lateral isolation regions, is disposed on a main surface of the substrate,placed in each section is at least one active component, e.g., a transistor of any type performance, andlateral deep diffusion regions which are accommodated in the semiconductor layer create a conductive connection between the highly conductive substrate and the corresponding regions of the active components.

Abstract: A lateral semiconductor device with enhanced breakdown characteristics includes a semiconductor substrate composite of first and second semiconductor substrates bonded to one another via an oxide film. An insulation film is buried in a separation trench which extends from a major surface of the first semiconductor substrate to the oxide film. An element region of 10 .mu.m or more in thickness is isolated by the separation trench from other element regions. First and second diffusion regions of opposite conductivity type are formed on the element region. The potential of the second substrate is fixed at one-third of the designed maximum breakdown voltage of the lateral semiconductor device. Alternatively, if the element region is 10 .mu.m or less in thickness, the potential of the second substrate is fixed at one-half of the designed maximum breakdown voltage of the lateral semiconductor device.

Abstract: A trench for element isolation is formed on the main surface of a semiconductor substrate. A conductive layer is formed in the trench, electrically connected to the semiconductor substrate. Oxide films and a dielectric film is formed between the conductive layer and the sidewall of the trench. A field oxide film is formed on the conductive layer. The dielectric film extends from the sidewall of the field oxide film to a region between the sidewall of the trench and the conductive layer. Consequently, a semiconductor device having an element isolation structure of superior isolation capability and high reliability can be obtained.

Abstract: Chips having subsurface structures within or adjacent a horizontal trench in bulk single crystal semiconductor are presented. Structures include three terminal devices, such as FETs and bipolar transistors, rectifying contacts, such as pn diodes and Schottky diodes, capacitors, and contacts to and connectors between devices. FETs have low resistance connectors to diffusions while retaining low overlap capacitance. A low resistance and low capacitance contact to subsurface electrodes is achieved by using highly conductive subsurface connectors which may be isolated by low dielectric insulator. Stacks of devices are formed simultaneously within bulk single crystal semiconductor. A subsurface CMOS invertor is described. A process for forming a horizontal trench exclusively in heavily doped p+ regions is presented in which porous silicon is first formed in the p+ regions and then the porous silicon is etched.

Abstract: A trench which has walls intersecting a surface of a semiconductor substrate and an oxidation/diffusion barrier layer lining the walls is disclosed. The oxidation/diffusion barrier extends over the edges of the trench to prevent, for example, stress defects in the trench corners and vertical bird's beak formation within the trench. A filler material such as polysilicon is deposited within the trench followed by the deposition of a planarizing layer over the trench. After heat is applied, the planarizing layer flows to form a planarized layer over the trench. Using high pressure and phosphosilicate glass for the planarizing layer, the planarizing layer flows appropriately at low temperatures for short times.

Abstract: An etch mask having a narrow spacer layer self-aligned and adjacent to a first portion of an inorganic first layered segment. An inorganic second layered segment comprises a portion of the etch mask and encompasses a perimeter of the first layered segment and is distanced from the first layered segment by a distance equal to a thickness of the narrow spacer layer. A first portion of the second layered segment is adjacent to the narrow spacer layer. A void exists between second portions of the first and the second layered segments. The area of the substrate exposed by the etch mask of the invention, when etched, forms a trench whose width is limited only by the width of the void which is equal to the width of the narrow spacer layer. The narrowness of the narrow isolated trench formed using the etch mask of the invention maximizes die space.

Abstract: A semiconductor substrate comprises a foundation, a semiconductor monocrystalline film formed on the foundation, and a high-melting-point metal film or a high-melting-point metal alloy film disposed in at least part of a region between the semiconductor monocrystalline film and the foundation. The high-melting-point metal film disposed below the semiconductor monocrystalline film can be utilized as a conductor in a semiconductor device.

Abstract: A high-resistant p-silicon layer is formed on a silicon substrate through a silicon oxide film. N-source and n-drain layers are selectively formed in the surface of the high-resistant p-silicon layer. A gate electrode is formed through a gate insulating film on a channel region between the source and drain layers. To induce an n-inverted layer under the gate electrode, a p-base layer is formed in the high-resistant p-silicon layer. A depletion layer extending from a pn junction between the n-drain layer and the high-resistant p-silicon layer reaches the silicon oxide film in a thermal equilibrium state. Part of the high-resistant p-silicon layer extends into a channel region between the drain and base layers. The drain and base layers are connected to each other through part of the depletion layer in the thermal equilibrium state. A field effect transistor having a high-speed operation is provided.

Abstract: It is an object of the present invention to provide a semiconductor device which has a high electrical isolation capability and an enhanced electrical reliability for avoiding short circuit of individual conductive layers, and the present invention also provides a method of manufacturing such a semiconductor device. An n.sup.+ buried layer and an n.sup.- epitaxial growth layer are formed on a p.sup.- silicon substrate. An element isolation oxide film having a through hole is formed on the surface of n.sup.- epitaxial growth layer. A trench which penetrates through n.sup.- epitaxial growth layer and n.sup.+ buried layer to reach a predetermined depth of p.sup.- silicon substrate is formed under through hole. A first insulating layer covers the internal wall of trench. A covering layer covers the sidewall of through hole. A filling layer is formed to fill trench so that the top surface thereof is located within through hole. A second insulating layer is formed on filling layer.

Abstract: Improved, planarized semiconductor structures are described which are prepared by a method involving the creation of a series of subminimum (i.e., 50 to 500 angstroms thick) polysilicon pillars extending vertically upward from the base of a wide trench and depositing a conductor material by chemical vapor deposition over the pillars; the pillars prevent the formation of a depression within the trench when planarized.

Abstract: A dielectric isolation substrate comprises a first semiconductor wafer, a second semiconductor wafer bonded on the first semiconductor wafer with a first insulating layer interposed therebetween, a semiconductor layer formed on the second semiconductor wafer, a first groove formed in the semiconductor layer and the second semiconductor wafer so as to reach the first insulating layer, thereby isolating the semiconductor layer and the second semiconductor wafer, and a second insulating layer formed on the side face of the first groove or embedded in the first groove. In this dielectric isolation substrate, a high breakdown voltage element and a low breakdown voltage element are formed in a region isolated by the first groove.

Abstract: A trenched DMOS transistor has improved device performance and production yield. During fabrication the cell trench corners, i.e. the areas where two trenches intersect, are covered on the principal surface of the integrated circuit substrate with a blocking photoresist layer during the source region implant step in order to prevent (block) a channel from forming in these corner areas. Punch-through is thereby eliminated and reliability improved, while source/drain on-resistance is only slightly increased. The blocking of the trench corners creates a cutout structure at each trench corner, whereby the source region does not extend to the trench corner, but instead the underlying oppositely-doped body region extends to the trench corner.

Abstract: Dielectrically isolated trench fill material is used for the formation of one or more isolated resistor elements within respective ones of a plurality of dielectrically isolated island components in which circuit devices are formed, or in adjacent substrate material. A respective island may have a plurality of trench strip resistor devices, which may have the same or differing resistor values depending upon their geometries or doping concentrations. In addition, the resistor-containing architecture may include one or more conductive cross-unders each defined by a respective cross-under trench strip. A cross-under trench strip contains conductive material, such as heavily doped polysilicon, as opposed to lightly doped polysilicon of the resistor fill material.

Abstract: An epitaxial conductor and a method for forming buried conductor patterns is described incorporating a layer of single crystalline silicon, a pattern formed therein such as a trench, a layer of metal silicide epitaxial formed on the bottom surface of the pattern or trench, a layer of silicon epitaxially formed thereover, and a layer of metal silicide epitaxially formed over the silicon layer. The invention overcomes the problem of twinning defects in the top surface of epitaxial silicide layers.

Abstract: A semiconductor substrate comprises a foundation, a semiconductor monocrystalline film formed on the foundation, and a high-melting-point metal film or a high-melting-point metal alloy film disposed in at least part of a region between the semiconductor monocrystalline film and the foundation. The high-melting-point metal film disposed below the semiconductor monocrystalline film can be utilized as a conductor in a semiconductor device.

Abstract: A semiconductor device for element isolation comprises a semiconductor substrate having an impurity region of a first conductivity type whose impurity concentration attains the maximum at a predetermined depth from the surface in the depth direction, a trench formed to a predetermined depth in the impurity region of the first conductivity type, and an impurity diffusion region of the first conductivity type formed in the trench with an oxide film interposed and having only its bottom portion connected to the impurity region of the first conductivity type of the semiconductor substrate. In the semiconductor device, a uniform P.sup.+ high concentration region is substantially formed in a bottom portion of an isolation region, so that an isolation threshold value is not affected.