Abstract: A method of fabricating semiconductor devices, such as conductors, fuses, capacitors, diodes, transistors, and the like, includes forming or obtaining a semiconductor wafer having a substrate material, an oxide layer, and a nitride layer. Mesas (the edges of which include active regions) are then formed by etching trenches (gaps) into the substrate material through the nitride and oxide layers. In accordance with one aspect of the present invention, the nitride layer is then pulled-back or retracted from the edges of the active regions thus exposing the corners of the active regions. The gaps and the edges of the active regions are then lined with a layer of oxide which rounds the corners of the active regions. The gaps are filled with another layer of oxide, and the semiconductor wafer is then planarized. Optionally, the edges of the active regions are then implanted with dopant.

Abstract: With the present invention, a filled isolation trench is fabricated as part of an integrated circuit on a semiconductor wafer using nitrogen implantation into at least one side wall of the isolation trench. An isolation trench is etched within a layer of semiconductor material. The isolation trench has at least one side wall comprised of the semiconductor material, and the isolation trench has a bottom wall. Nitrogen ions are implanted into the at least one side wall of the isolation trench. A layer of an insulator material is thermally grown from the at least one side wall and the bottom wall of the isolation trench. The isolation trench is then filled with the insulator material using a deposition process to form the filled isolation trench. With the present invention, the nitrogen ions implanted into the at least one side wall of the isolation trench reduce a radius of a bird's beak formed on the at least one side wall of the isolation trench.

Abstract: A polycrystalline silicon film is formed on a surface of a trench and on a surface of a silicon nitride film. A silicon substrate covered with a polycrystalline silicon film is thermally oxidized at 900 to 1100° C. in an oxygen ambient to provide an uneven interface between a thermally oxidized silicon film and the silicon substrate. Thus a semiconductor device can be obtained capable of reducing a compressive stress caused in the semiconductor substrate near an element isolating trench region to minimize formation of crystal defect.

Abstract: A process for creating a substrate including bulk silicon regions and semiconductor-on-insulator regions. Regions of a surface of a bulk silicon substrate are recessed above regions where it is desired to create buried oxide regions in the substrate. Implant mask regions are formed on the surface of the substrate over regions where it is not desired to create buried oxide regions. Buried oxide regions are formed in the substrate under the recessed regions in the substrate. The implant mask regions are removed, leaving bulk silicon regions between the buried oxide regions.

Abstract: A semiconductor fabrication method is provided for the fabrication of an isolation structure including a shallow-trench isolation (STI) structure in an integrated circuit. This method is characterized by the increase in the thickness of the adhesive layer over that of the prior art and also in the use of thermal oxidation process to form the STI structure. The thick adhesive layer can thus resist the stress from thermal expansion of the various component layers in the integrated circuit during heat treatment. Moreover, the resulting STI structure is not formed with recessed edge portions since the hydrofluoric (HF) etchant acts on the silicon dioxide plug in the STI structure with substantially the same etching rate as on the adhesive layer. Moreover, this method includes no chemical-mechanical polish (CMP) process, so the problem of scratches on the surface of the silicon dioxide plug as seen in the case of the prior art is avoided.

Abstract: A method of manufacturing shallow trench isolation structure comprising the steps of forming a polysilicon mask layer over a substrate, and then patterning the polysilicon mask layer and the substrate to form a trench. Thereafter, a silicon nitride layer is formed covering the sidewalls of the trench. Next, a high-density chemical vapor deposition method is used to deposit oxide material into the trench. Finally, the surface is polished to remove a portion of the oxide layer and the silicon nitride layer until the polysilicon mask layer is exposed. The shallow trench isolation structure can avoid subthreshold kink effect and reduce subthreshold leakage current.

Abstract: A method of manufacturing semiconductor components includes etching two trenches (105, 106, 805, 806, 1205, 1206) into a surface of a substrate (101, 801, 1201), lining the two trenches (105, 106, 805, 806, 1205, 1206) with an electrically insulative layer (107, 807, 1207) that is never completely removed from a first one of the two trenches (105, 106, 805, 806, 1205, 1206), and simultaneously filling the two trenches (105, 106, 805, 806, 1205, 1206) with a material wherein the material is never completely removed from the first one of the two trenches (105, 106, 805, 806, 1205, 1206) and wherein the second one of the two trenches (105, 106, 805, 806, 1205, 1206) becomes electrically coupled to the substrate (101, 801, 1201).

Abstract: A method of forming an isolation structure for isolating high voltage devices is described. A first p-well is formed in and on a substrate. Two field oxides are formed spaced apart from each other over the first p-well. A second p-well is formed in and on the first p-well, wherein the second p-well substantially surrounds and substantially being adjacent to the field oxides in the first p-well. A trench isolation is formed in and on the first p-well and between the field oxides, wherein the trench isolation is substantially deeper than the second p-well. A third p-well substantially surrounding and being adjacent to the trench isolation is formed in the first p-well.

Abstract: Methodology for achieving dual field oxide thicknesses comprises forming field oxide isolation regions to a common thickness. An oxidation barrier layer, which may comprise nitride or oxynitride, is formed on selected field oxide regions leaving others exposed. The exposed field oxide regions are enlarged in a complementary thermal oxidation step, wherein the isolation regions covered by the oxidation barrier layer are not enlarged, thereby achieving field oxide regions of at least two thicknesses.

Abstract: A process is disclosed for fabricating buried diffusion junction that can be combined with the shallow-trench isolation for the memory device cell unit transistor wherein both the junction and the isolation can be formed in the same layout. The buried diffusion is free from being inadvertently cut apart to cause open-circuiting. A bird's beak oxide layer is formed protecting the buried diffusion junction region from undesirable etching, thereby preventing from damaging consumption by etching. The buried diffusion junctions formed may serve as the source/drain region for the transistor.

Abstract: The stress dislocations formed in a substrate by semiconductor processing are significantly reduced, if not eliminated, by subjecting the substrate to a high temperature post sacrificial oxide anneal that causes viscous flow of the oxide over the substrate. In one example embodiment, a method of forming a semiconductor structure includes forming a first oxide layer over a substrate and forming a first dielectric material layer over the first oxide layer. An opening is then etched in the oxide and dielectric layers thereby exposing the substrate. A trench is formed with a desired depth in the substrate in the opening provided, followed by a deposition of an insulator material in the trench. The first dielectric layer and a portion of the insulator material is then removed leaving a portion of the insulator material within the trench. Applications include logic circuits having embedded-DRAM and circuits directed to stand-alone logic or stand-alone DRAM.

Abstract: The present invention provides an SOI device and its isolation method capable of solving both Well-resistance and punch-through problems. To realize foregoing device, there is provided a semiconductor layer that a region in which a field oxide film having relatively wider width is formed later, is thicker than a region in which a field oxide film having relatively narrower width is formed later. Those field oxide films having different widths with an equal thickness are formed on the field regions of the semiconductor layer. Herein, the thickness of the semiconductor layer below the field oxide film having relatively wider width is thicker than the thickness of the semiconductor layer below the field oxide film having relatively narrower width owing to the fact that the semiconductor layer has various thicknesses according to the respective regions.

Abstract: A method of fabricating shallow trench isolation. A silicon oxide layer is formed on a substrate. The silicon oxide layer is patterned and a portion of the substrate is removed to form a trench within the substrate. A liner oxide layer is formed on the sidewall of the trench. An insulating layer is formed on the substrate and filled in the trench. A portion of the insulating layer is removed by CMP to expose the silicon oxide layer. The silicon oxide layer is removed and the STI structure is completed.

Abstract: A method of forming a planar silicon nitride layer is disclosed. The method comprises: forming a pad oxide layer; forming a first nitride layer on the pad oxide layer; forming a stop layer on the first nitride layer; forming a second nitride layer on the stop layer; performing intermediate processes that damage the second nitride layer; removing the second nitride layer; removing the stop layer such that the first nitride layer remains as the planar silicon nitride layer.

Abstract: The present invention provides a method of forming an isolation region comprising a trench isolation region involved in a semiconductor device. A silicon oxide film is grown on a surface of a trench groove formed within a semiconductor substrate, followed by a deposition of a nitride film material. An oxide film is formed on the silicon oxide film of the wide trench groove region. The nitride film within the trench groove region, so as to form a device isolation film is etched, sequentially, a oxide film is deposited on the entire exposed surface of the trench region, and the oxide film except within the trench groove, is etched by using chemical mechanical polishing (CMP).

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 semiconductor device is manufactured by forming a gate oxide film on a semiconductor substrate; forming a gate electrode on the gate oxide film; forming a first nitride film on the gate electrode; etching the gate electrode and the first nitride film through a same mask; depositing a second nitride film on at least a side wall of the gate electrode for covering the same; forming an opening in the second nitride film by etching such that the second nitride film is left on the side wall of the gate electrode; and forming a thick oxide film, i.e. LOCOS film, on a bottom of the opening in the second nitride film by a thermal oxidation. The alignment mismatch between the LOCOS film and the gate electrode is prevented, and the overlap length of the LOCOS film and the gate electrode is shortened to a half or less of the overlap length in the conventional device.

Abstract: Using sub-micron technology, silicon on insulator (SOI) rows and islands are formed in a silicon substrate. Trenches are directionally-etched in the silicon substrate, leaving rows of silicon between the trenches. Silicon nitride is then deposited over the trenches, extending partly down the sides of the trenches. An isotropic chemical etch is then used to partially undercut narrow rows of silicon in the substrate. A subsequent oxidation step fully undercuts the rows of silicon, isolating the silicon rows from adjacent active areas. Devices, such as transistors for CMOS and DRAMs, are then formed in active areas, wherein the active areas are defined on the silicon rows by LOCal Oxidation of Silicon (LOCOS).

Abstract: A method of shallow trench isolation by forming a trench in a semiconductor device comprises the steps of forming an oxide layer; forming a mask layer; anisotropically etching the mask layer; forming a second oxide layer; forming a cap layer; forming rounded end caps adjacent the mask; and transferring the rounding of the caps to the top corners of the trench. The oxide layer is formed over a substrate of the semiconductor device. The mask layer is formed over the oxide layer. The mask layer is then anisotropically etched to form the mask and an opening in the mask. The opening in the mask exposes the substrate, and the width of the opening is greater than the width of the trench. Blanket etching the cap layer forms the rounded end caps. The rounded end caps are adjacent to the mask on opposite ends of the opening, and the distance between the end caps is about equal to the width of the trench. The trench is formed by plasma etching the trench.

Abstract: A method of forming an improved trench isolation structure between transistors on an IC is disclosed. The isolation trench is formed without significantly degrading, or thinning the previously deposited gate oxide layer. The gate oxide layer is deposited on the silicon substrate and covered with a first polysilicon layer. A trench is etched through the first polysilicon layer and gate oxide layer, into the silicon substrate. The edges of the silicon substrate and polysilicon layer, exposed by the trench, are oxidized. The trench is filled with oxide and a CMP is performed. After the CMP, a second layer of polysilicon is deposited. The transistor is then etched to form a gate electrode including both layers of polysilicon. The formation of oxide on the trench sidewalls prevents the degradation of the gate oxide layer in the subsequent CMP and IC fabrication processes. The transistor has a high breakdown voltage and low leakage current.

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: 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: Ions are implanted into a silicon nitride film at a dose of not more than 1.times.10.sup.15 cm.sup.-2 so that the projected range of the ions is 20 to 60% of the thickness of the silicon nitride film. This enables the stress of the nitride film to be reduced while enjoying good productivity without introduction of defects into a silicon substrate.

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: A method of manufacturing shallow trench isolation comprising the steps of forming a pad oxide layer and a mask layer over a substrate, then patterning the pad oxide layer and the mask layer forming an opening in the substrate. Thereafter, insulating material is deposited into the opening forming an insulating layer, and then the mask layer is removed to expose the pad oxide layer. Next, insulating spacers are formed on the sidewalls of the insulating layer. Subsequently, the insulating spacers and the pad oxide layer are removed to complete the formation of shallow trench isolation. Hence, a trench-filled insulating layer having a smooth upper surface is formed. By forming insulating spacers over the junction area between the substrate and the insulating layer, over-etching of the junction is avoided.

Abstract: An isolation structure providing electrical isolation in two dimensions between memory cells in semiconductor memory devices. The isolation structure comprises a trench formed in a substrate of a semiconductor memory device such as a Dynamic Random Access Memory (DRAM). The trench is lined with an insulating material and filled with polysilicon to form a floating gate. An electrical charge is then injected into the polysilicon floating gate. The isolation structure is located between memory cells in an array to provide isolation between cells in sub-micron spacing by combining the characteristics of trench and field isolation. The electrical charge is injected into the polysilicon floating gate by applying a charging voltage to the wordlines of the memory cell array. The charging voltage is applied periodically as necessary to maintain effective isolation. Two dimensional isolation is achieved by extending the trench to surround each pair of memory cells sharing a common bitline contact.

Abstract: The top surface of a P-type semiconductor substrate is partitioned into an active region to be formed with an element and an isolation region surrounding the active region. The isolation region is composed of trench portions and dummy semiconductor portions. An interlayer insulating film is deposited on the substrate, followed by a wire formed thereon. In each of the semiconductor portions, an impurity diffusion layer is formed simultaneously with the implantation of ions into the element so that a PN junction is formed between the impurity diffusion layer and the silicon substrate. A capacitance component of the wiring-to-substrate capacitance in the region containing the semiconductor portions is obtained by adding in series the capacitance in the impurity diffusion layer to the capacitance in the interlayer insulating film, which is smaller than the capacitance only in the inter layer insulating film.

Abstract: A method for forming an isolation region of a semiconductor device includes the steps of forming first and second insulating layers on a substrate, removing the second insulating layer over an isolation region, forming an oxide layer by oxidizing the first insulating layer over the isolation region, forming sidewall spacers at sides of the second insulating layer and over the isolation region, forming a trench by etching the oxide layer and the substrate at the isolation region, removing the sidewall spacers, forming a third insulating layer on the substrate in the trench, and forming an isolation layer in the trench.

Abstract: A thin silicon dioxide layer is formed on a substrate to act as a pad oxide layer. Subsequently, a Si.sub.3 N.sub.4 or BN layer is deposited on the pad oxide layer. An in situ doped polysilicon layer is deposited on the Si.sub.3 N.sub.4 or BN layer. A trench is formed in the substrate. An oxide liner is formed along the walls of the trench and on the surface of the in situ doped polysilicon layer. A CVD oxide layer is formed on the oxide liner and refilled into the trench. A two-step chemical mechanical polishing (CMP) removes the layers to the surface of the Si.sub.3 N.sub.4 or BN layer. The first step of the two-step CMP is an oxide slurry CMP that is stopped at about 100 to 500 angstroms from the in situ doped polysilicon layer. The second step of the two-step CMP is a poly slurry CMP that is controlled to stop at the surface of the Si.sub.3 N.sub.4 or BN layer.

Abstract: A method for fabricating a field device transistor includes forming a gate oxide layer of the field device transistor by performing a thermal oxidation process. By properly controlling the thickness of the gate oxide layer, the threshold voltage of the field device transistor can be suppressed in under 5 volts to provide sufficient protection for the internal circuit. The method of the invention includes forming a gate oxide layer of a field device transistor by performing a thermal oxidation process instead of a field oxide layer in order to obtain a better control on the thickness of the gate oxide layer.

Abstract: A method for forming a field oxide of a semiconductor device and the semiconductor device. In order to form the field oxide, first, an element isolation mask is constructed on a semiconductor substrate. Then, a nitride spacer is formed at the side wall of the mask. At this time, a nitrogen-containing polymer is produced on the field region. The exposed region of the semiconductor substrate is oxidized at a temperature of 1,050-1,200.degree. C. to grow a recess-oxide while transforming the nitrogen-containing polymer into a nitride. Thereafter, the recess oxide is removed, together with the nitride, to create a trench in which the field oxide is formed through thermal oxidation. Therefore, the method can prevent an FOU phenomenon upon the growth of a field oxide and improve the field oxide thinning effect, thereby bringing a significant improvement to the production yield and the reliability of a semiconductor device.

Abstract: A method for filling a trench within a silicon substrate. There is first provided a silicon substrate having a trench formed therein. There is then oxidized thermally the silicon substrate to form within the trench a thermal silicon oxide trench liner layer. There is then treated the thermal silicon oxide trench liner layer by exposure to a plasma formed from a gas composition which upon plasma activation simultaneously supplies an active nitrogen containing species and an active oxygen containing species to form a plasma treated thermal silicon oxide trench liner layer. There is then formed upon the plasma treated thermal silicon oxide trench liner layer a conformal silicon oxide intermediate layer formed through a plasma enhanced chemical vapor deposition (PECVD) method employing a silane silicon source material.

Abstract: A method of forming a circuitry isolation region within a semiconductive wafer comprises defining active area and isolation area over a semiconductive wafer. Semiconductive wafer material within the isolation area is wet etched using an etch chemistry which forms an isolation trench proximate the active area region having lowestmost corners within the trench which are rounded. Electrically insulating material is formed within the trench over the previously formed round corners. In accordance with another aspect, the semiconductive wafer material within the isolation area is etched using an etch chemistry which is substantially selective relative to semiconductive wafer material within the active area to form an isolation trench proximate the active area region. In accordance with still another aspect, a method of forming a circuitry isolation region within a semiconductive wafer comprises masking an active area region over a semiconductive wafer.

Abstract: A method for forming a shallow trench isolation structure. A pad oxide layer is formed over a substrate. A hard mask layer is formed over the pad oxide layer. A portion of the hard mask layer, the pad oxide layer and the substrate is removed to form a trench in the substrate. Insulation material is deposited into the trench to form an insulation plug. The hard mask layer is removed to expose the sidewalls of the insulation plug. Spacers are formed on the exposed sidewalls of the insulation plug. Ions are implanted into the substrate. The pad oxide layer, the spacers and a portion of the insulation plug are removed. Finally, a gate oxide layer thicker in region around the edge of the insulation plug is formed over the substrate by oxidation.

Abstract: A structure and a method for fabricating integrated circuits are disclosed in which narrow trench isolation structures (36) are formed between active regions (38) of an integrated circuit (10). A silicon nitride layer is deposited, patterned and etched to provide nitride mask (16) having spaces (20) which are preferably no larger than the minimum photolithography spacing limits. Single sidewall oxide spacers (24) are formed on the sidewalls of the nitride mask by depositing a conformal coating of oxide and then applying an anisotropic etch, leaving the oxide spacers (24) of approximately 100 to 500 Angstroms thickness on the sidewalls of the nitride mask (16). Isolation trenches (26) are etched into a silicon substrate (12) in the spaces between adjacent ones of the oxide spacers (24). The oxide spacers (24) are then removed without removing the nitride mask (16), leaving ledges, or shelf regions (28), of the substrate (12) in the spaces between the trenches (26) and the nitride mask (16).

Abstract: The present invention relates generally to removing an undesirable second oxide, while minimally affecting a desirable first oxide, on an integrated circuit. The integrated circuit may be part of a larger system.The second oxide is first converted to another material, such as oxynitride. The other material has differing characteristics, such as etching properties, so that it can then be removed, without substantially diminishing the first oxide.The conversion may be accomplished by heating. Heating may be accomplished by rapid thermal or furnace processing. Subsequently, the other material is removed from the integrated circuit, for example by hot phosphoric etching, so that the desirable first oxide is not substantially affected.

Abstract: A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede such that a portion of the semiconductor substrate is exposed. An etch through the exposed portion of the semiconductor substrate forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. The microtrench is then filled by oxide or nitride growth or by deposition of a dielectric material. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is removed immediately following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate.

Abstract: A shallow groove isolation structure (SGI) electrically insulates adjoining transistors on a semiconductor substrate. A pad oxide film is formed on the semiconductor substrate and an oxidation inhibition film is formed on the pad oxide film. Parts of the oxide inhibition film and pad oxide film are removed to form the groove. In particular, the pad oxide film is removed from an upper edge of the groove within a range of 5 to 40 nm. A region of the groove is oxidized in an oxidation environment with a cast ratio of hydrogen (H.sub.2) to oxygen (O.sub.2) being less than or equal to 0.5. At this ratio, the oxidizing progresses under low stress at the upper groove edges of the substrate thereby enabling rounding of the upper groove edges without creating a level difference at or near the upper groove edge on the substrate surface.

Abstract: A process for creating an insulator filled, shallow trench, in a semiconductor substrate, in which the insulator layer in the shallow trench, is not exposed to procedures used to remove defining composite insulator layers, has been developed. The process features creating a lateral recess, in a thick silicon nitride layer, used as a component of a composite insulator layer, where the composite insulator layer is used for subsequent definition of the shallow trench, in the semiconductor substrate.

Abstract: A method to reduce to reduce DRAM capacitor STI junction leakage current. A Shallow Trench Isolation opening is formed, within this opening Field Oxide is deposited. The top surface of the FOX is etched down and a second layer of oxide is deposited over the FOX and the adjacent active regions. This second layer of oxide is etched bringing the top surface down to below the level of the top surface of the surrounding active areas but leaving spacers where the top surface of the FOX intersects with the active areas.

Abstract: A method to prevent the formation of a thinner portion of insulating layer, especially a gate oxide layer, at the junction between the side walls and the bottom insulator is disclosed. First, a pad oxide layer is formed on the side walls and the bottom of the trench. Next, a bottom oxide is formed on the lower portion of the trench. Then, the upper portion of the bottom oxide and the exposed pad oxide layer are removed by wet etching to leave a bottom oxide having a concave surface. Next, the conformal gate oxide layer is grown on the exposed side walls of the trench.

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: Into the portion of a silicon substrate which lies in the vicinity of a trench isolation portion, ions such as argon for enhancing the oxidation rate are implanted. Or, nitrogen ions for lowering the oxidation rate are implanted into the portion of the silicon substrate other than the portion thereof lying in the vicinity of the trench isolation portion. Thereafter, thermal oxidation is performed, so that a gate insulation film is formed in such a manner that the thickness thereof becomes equal to or greater than the thickness of the center portion thereof. Thus, the deterioration of the breakdown voltage of the insulation film can be prevented, because the gate insulation film becomes thin in the end portion of the gate electrode.

Abstract: A method for forming planarized isolation by combining LOCOS and STI isolation processes is described. A first nitride layer is deposited over a pad oxide layer on the surface of a semiconductor substrate. The first nitride layer and pad oxide layer are etched through where they are not covered by a mask to provide openings where the surface of the semiconductor substrate is exposed wherein there is at least one wide opening and one narrow opening. A second nitride layer is deposited over the substrate and etched back to leave spacers on the sidewalls of the openings wherein the narrow opening is filled by the spacers. The exposed semiconductor substrate within the wide opening is oxidized wherein a field oxide region is formed within the wide opening. A portion of the first nitride layer and spacers is etched away whereby the semiconductor substrate within the narrow opening is exposed. A trench is etched into the semiconductor substrate where it is exposed within the narrow opening.

Abstract: A method of planarizing a non-conformal oxide layer 40 forming shallow trench isolation between active areas 12 in a substrate. The invention uses a first chemical-mechanical polish (CMP) step to form openings 50 only over wide active areas. An etch is used to remove oxide 40 from only over the wide active areas 12A. A second CMP step is used to planarized the oxide layer 40. The invention begins by forming spaced trenches 30 in said substrate 10 defining active areas 12. A first insulating layer 40 composed of a non-conformal silicon oxide is formed by a HDPCVD process over the substrate and fills the trenches 30. A etch barrier layer 44 is formed over the first insulating layer 40. In a first chemical-mechanical polish (CMP) step, the conformal etch barrier layer 44 over only the wide raised portions 12A is polished to form a self-aligned first openings 50. The chemical-mechanical polishing of the conformal etch barrier layer forms a self-aligned etch mask.

Abstract: The present invention is directed to am improved chemical mechanical polish etch stop for a trench isolation and a method for making same. The method comprises forming at least four process layers above a surface of a semiconducting substrate. The method further comprises patterning said plurality of process layers to define an opening exposing a portion of the surface of the substrate. A trench is formed in the substrate, and the trench and the opening are then filled with a dielectric material. The surface of the dielectric material and the surface of the top process layer are then planarized. The present inventive structure is comprised of at least four process layers positioned above a substrate, an opening formed in said plurality of layers, a trench formed in said substrate, and a dielectric material positioned in said opening and said.

Abstract: A method of forming a shallow trench isolation in a semiconductor substrate. A mask layer is formed to cover an active region of the substrate. A trench is formed within the exposed substrate. The trench is filled with an insulation layer. The dimension of the mask layer is shrunk. A thermal oxidation process is performed to form an oxide protrusion between the trench and the active region. The mask layer is removed.

Abstract: A method is provided for forming a shallow trench isolation that has rounded and protected corners by first forming a bird's beak field oxide layer prior to the trench-forming step such that a rounded and protected top corner and a rounded bottom corner of the trench can be formed. The rounded top and bottom corners of the shallow trench opening have a radius of at least 100 .ANG. and a trench depth of not more than 5000 .ANG.. The top corner of the trench opening is protected by the beak portion of the bird's beak against etching in a subsequent oxide dip process before gate formation.

Abstract: A method to form shallow trench isolation structures with improved isolation fill and surface planarity is described. A pad oxide layer is provided over the surface of a semiconductor substrate. A silicon nitride layer is deposited overlying the pad oxide layer. A thin oxide layer is deposited overlying the silicon nitride layer. An isolation trench is etched through the thin oxide layer, the nitride layer, and the pad oxide layer and into the substrate. The silicon nitride layer exposed within the trench is etched to form a lateral undercut leaving a projection of the thin oxide layer and exposing a portion of the underlying pad oxide layer. The thin oxide layer and the exposed portion of the pad oxide layer are etched away thereby exposing portions of the surface of the substrate. A liner oxide is grown on the exposed portions of the semiconductor substrate within the isolation trench and on the surface of the substrate.

Abstract: A method of selective oxidation includes forming a mask layer which includes a silicon oxide film pattern and a silicon nitride film pattern on an active region defined on silicon substrate, a forming a trench using the mask layer in an isolation region defined in the silicon substrate adjoining the active region, forming a buried silicon oxide film in the trench, forming a buried poly-silicon film on the buried silicon oxide film in the trench, converting the buried poly-silicon film to a field oxide film, and removing the mask layer. The occurrence of a bird's beak during selective oxidation of the silicon can be prevented.