Abstract: A method of forming source/drain regions in a semiconductor device is provided. In one illustrative embodiment, the method comprises forming a gate electrode above a semiconducting substrate, forming source/drain regions in the substrate adjacent the gate electrode by performing at least the following steps: performing two ion implantation processes to form source/drain extensions for the device and performing a third ion implantation process to further form source/drain regions for the device. Various N-type and P-type dopant atoms such as arsenic, phosphorous, boron and boron difluoride may be used with the present invention.

Abstract: An insulated trench isolation structure is formed by ion implanting impurities proximate to the trench edges for enhancing the oxidation rate and, hence, increasing the thickness of the oxide at the trench edges. Embodiments include ion implanting impurities prior to growing an oxide liner. The resulting thick oxide on the trench edges avoids overlap of a subsequently deposited polysilicon layer and breakdown problems attendant upon a thinned gate oxide at the trench edges.

Abstract: An insulated trench isolation structure with large and small trenches of differing widths is formed in a semiconductor substrate with improved planarity using a simplified reverse source/drain planarization mask. Embodiments include forming large trenches and refilling them with an insulating material which also covers the substrate surface, masking the areas above the large trenches, etching to remove substantially all of the insulating material on the substrate surface and polishing to planarize the insulating material above the large trenches. Small trenches and peripheral trenches surrounding the large trenches are then formed, refilled with insulating material, and planarized. Since the large trenches are formed prior to and separately from the small trenches, etching can be carried out after the formation of a relatively simple planarization mask over only the large trenches, and not the small trenches.

Abstract: A dielectric material is provided having air gaps purposely formed within the dielectric. The dielectric is deposited, and air gaps formed, between respective interconnect lines. The geometries between interconnect lines is purposely controlled to achieve a large aspect ratio necessary to produce air gaps during CVD of the dielectric. Air gaps exist between interconnects to reduce the line-to-line capacitance, and thereby reduce the propagation delay associated with closely spaced interconnects.

Abstract: An isolation technique is provided for improving the overall planarity of isolation regions relative to adjacent active area silicon mesas. The isolation process results in a trench formed in field regions immediately adjacent the active regions. The trench, however, does not extend entirely across the field region. By preventing large area trenches, substantial dielectric fill material and the problems of subsequent planarization of that fill material is avoided. Accordingly, the present isolation technique does not require conventional fill dielectric normally associated with a shallow trench process. While it achieves the advantages of forming silicon mesas, the present process avoids having to rework dielectric surfaces in large area field regions using conventional sacrificial etchback, block masking and chemical-mechanical polishing. The improved isolation technique hereof utilizes trenches of minimal width etched into the silicon substrate at the periphery of field regions, leaving a field mesa.

Abstract: A method for forming a multilevel interconnect structure having a globally planarized upper surface. Dielectrics are deposited upon a semiconductor to minimize pre-existing disparities in topographical height and to create an upper surface topography having a polish rate greater than that of lower regions. Subsequent chemical mechanical polishing produces a substantially planar surface.

Abstract: A method of making a semiconductor device with improved isolation region to active region topography includes forming a masking layer on a surface of a substrate. A portion of the masking layer is removed to define one or more field regions and at least one trench is formed in the one or more field regions. An oxide layer is formed which substantially fills the trench and then a portion of the oxide layer is removed to leave the oxide layer with a relatively planar surface that is recessed with respect to the masking layer. The masking layer is then removed to expose the substrate. There may be a height differential between the substrate surface and the relatively planer surface of the oxide layer, however, the height differential is substantially less than the thickness of the masking layer.

Abstract: An isolation technique is provided for improving the overall planarity of isolation regions relative to adjacent active area silicon mesas. The isolation process results in a trench formed in field regions immediately adjacent the active regions. The trench, however, does not extend entirely across the field region. By preventing large area trenches, substantial dielectric fill material and the problems of subsequent planarization of that fill material is avoided. Accordingly, the present isolation technique does not require conventional fill dielectric normally associated with a shallow trench process. While it achieves the advantages of forming silicon mesas, the present process avoids having to rework dielectric surfaces in large area field regions using conventional sacrificial etchback, block masking and chemical-mechanical polishing. The improved isolation technique hereof utilizes trenches of minimal width etched into the silicon substrate at the periphery of field regions, leaving a field mesa.

Abstract: A reduced permittivity interlevel dielectric in a semiconductor device arranged between two levels of interconnect. The dielectric comprises a first dielectric layer preferably from a silane source deposited on a first level interconnect to form air gaps at midpoints between adjacent first interconnect structures, a second dielectric containing air gap trenches at spaced intervals across the second dielectric, and a third dielectric formed upon said second dielectric. A second interconnect level is formed on the third dielectric.

Abstract: An insulated trench isolation structure with large and small trenches of differing widths is formed in a semiconductor substrate without a planarization mask or etch. Embodiments include forming trenches and refilling them with an insulating material which also covers the substrate surface, followed by polishing to remove an upper portion of the insulating material and to planarize the insulating material above the small trenches. A second layer of insulating material is then deposited to fill seams in the insulating material above the small trenches and to fill steps in the insulating material above the large trenches. The insulating material is then planarized.

Abstract: A method of forming an improved isolation trench between active regions within the semiconductor substrate involves oxidizing unmasked portions of a semiconductor substrate prior to etching an isolation trench into the semiconductor substrate. By oxidizing the unmasked portions of the semiconductor prior to etching, an isolation trench with rounded corners may be formed.

Abstract: A method for effectively generating limited trench width isolation structures without incurring the susceptibility to dishing problems to produce high quality ICs employs a computer to generate data representing a trench isolation mask capable of being used to etch a limited trench width isolation structure about the perimeter of active region layers, polygate layers, and Local Interconnect (LI) layers. Once the various layers are defined using data on the computer and configured such that chip real estate is maximized, then the boundaries are combined using, for example, logical OR operators to produce data representing an overall composite layer. Once the data representing the composite layer is determined, the data is expanded evenly outward in all horizontal directions by a predetermined amount, .lambda., to produce data representing a preliminary expanded region.

Abstract: An improved multilevel interconnect structure is provided. The interconnect structure includes several levels of conductors, wherein conductors on one level are staggered with respect to conductors on another level. Accordingly, a space between conductors on one level is directly above or directly below a conductor within another level. The staggered interconnect lines are advantageously used in densely spaced regions to reduce the interlevel and intralevel capacitance. Furthermore, an interlevel and an intralevel dielectric structure includes optimally placed low K dielectrics which exist in critical spaced areas to minimize capacitive coupling and propagation delay problems. The low K dielectric, according to one embodiment, includes a capping dielectric which is used to prevent corrosion on adjacent metallic conductors, and serves as an etch stop when conductors are patterned.

Abstract: An improved multilevel interconnect structure is provided. The interconnect structure includes several levels of conductors, wherein conductors on one level are staggered with respect to conductors on another level. In densely spaced interconnect areas, interposed conductors are drawn to dissimilar elevational levels to lessen the capacitive coupling between the interconnects. By staggering every other interconnect line in the densely patterned areas, the interconnects are capable of carrying a larger amount of current with minimal capacitive coupling therebetween.

Abstract: An insulated trench isolation structure is formed by ion implanting impurities proximate the trench edges to enhance the silicon oxidation rate and, hence, increase the thickness of the resulting oxide at the trench edges. Embodiments include masking and etching a barrier nitride layer, forming protective spacers on portions of the substrate corresponding to subsequently formed trench edges, etching the trench, removing the protective spacers, ion implanting impurities into those portions of the substrate previously covered by the protective spacers, and then growing an oxide liner. The resulting oxide formed on the trench edges is thick due to the enhanced silicon oxidation rate, thereby avoiding overlap of a subsequently deposited polysilicon layer and breakdown problems attendant upon a thinned gate oxide at the trench edges.

Abstract: An insulated trench isolation structure is formed in a semiconductor substrate with an oxide or nitride spacer overlying and protecting a portion of a pad oxide layer at the trench edge such that the pad oxide layer acts as part of the gate oxide layer. Embodiments include providing a step between the trench fill and the pad oxide layer and forming the protective spacer thereon. The protective spacer protects the underlying portion of the pad oxide layer at the trench edge during pad oxide removal prior to forming a gate oxide. Therefore, it is only necessary to grow the gate oxide on the main surface of the substrate, not at the trench edges. The gate oxide can then be formed uniformly thin, while the remaining pad oxide at the trench edges is relatively thick.

Abstract: A subfield conductive layer is provided, wherein a conductive layer is implanted beneath and laterally adjacent a field dielectric. The subfield conductive layer is placed within the silicon substrate after the field dielectric is formed. The conductive layer represents a buried interconnect which resides between isolated devices. The buried interconnect, however, is formed using high energy ion implant through a field dielectric formed either by LOCOS or shallow trench isolation techniques. The buried interconnect, or conductive layer, resides and electrically connects source and drain regions of two isolated devices.

Abstract: A interconnect structure is provided having a conductor with enhanced thickness. The conductor includes an upper portion and a lower portion, wherein the lower portion geometry is sufficient to increase the current-carrying capacity beyond that provided by the upper portion. The lower portion is formed by filling a trench within an upper dielectric region, and the upper portion is formed by selectively removing a conductive material from the upper dielectric surface except for regions directly above the lower portion. The upper and lower portions thereby form a conductor of enhanced cross-section which can be produced by modifying a via-etch mask, rather than having to reconfigure and/or move interconnect features formed by a metal mask.

Abstract: An insulated trench isolation structure with large and small trenches of differing widths is formed in a semiconductor substrate using a simplified reverse source/drain planarization mask. Embodiments include forming trenches and refilling them with an insulating material which also covers a main surface of the substrate, polishing to remove an upper portion of the insulating material and to planarize the insulating material above the small trenches, furnace annealing to densify and strengthen the remaining insulating material, masking the insulating material above the large trenches, isotropically etching the insulating material, and polishing to planarize the insulating material. Since the insulating material is partially planarized and strengthened prior to etching, etching can be carried out after the formation of a relatively simple planarization mask over only the large trenches, and not the small trenches.

Abstract: An insulated trench isolation structure is formed in a semiconductor substrate omitting a barrier nitride polish stop layer while avoiding substrate damage, thereby simplifying trench formation and improving planarity. After trench fill, polishing is conducted to effect substantial planarization without exposing the substrate surface, thereby avoiding substrate damage. Etching is then conducted to expose the substrate surface. The omission of the barrier nitride polish stop avoids generation of a topographical step at the substrate/trench fill interface, thereby enhancing the accuracy of subsequent photolithographic techniques in forming features with minimal dimensions.