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: A method of making an IGFET using solid phase diffusion is disclosed. The method includes providing a device region in a semiconductor substrate, forming a gate insulator on the device region, forming a gate on the gate insulator, forming an insulating layer over the gate and the device region, forming a heavily doped diffusion source layer over the insulating layer, and driving a dopant from the diffusion source layer through the insulating layer into the gate and the device region by solid phase diffusion, thereby heavily doping the gate and forming a heavily doped source and drain in the device region. Preferably, the gate and diffusion source layer are polysilicon, the gate insulator and insulating layer are silicon dioxide, the dopant is boron or boron species, and the dopant provides essentially all P-type doping for the gate, source and drain, thereby providing shallow channel junctions and reducing or eliminating boron penetration from the gate into the substrate.

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 diffusion-retarding barrier region is incorporated into the gate electrode to reduce the downward diffusion of dopant toward the gate dielectric. The barrier region is a nitrogen-containing diffusion retarding barrier region formed between two separately formed layers of polysilicon. The upper layer of polysilicon is doped more heavily than the lower layer of polysilicon, and the barrier region serves to keep most of the dopant within the upper layer of polysilicon, and yet may allow some of the dopant to diffuse into the lower layer of polysilicon. The barrier region may be formed, for example, by annealing the first polysilicon layer in an nitrogen-containing ambient to form a nitrided layer at the top surface of the first polysilicon layer. The barrier region may alternatively be formed by depositing a nitrogen-containing layer, such as a silicon nitride or titanium nitride layer, on the top surface of the first polysilicon layer.

Abstract: An IGFET with a silicide contact on an ultra-thin gate is disclosed. A method of forming the IGFET includes forming a gate over a semiconductor substrate, forming a source and a drain in the substrate, depositing a contact material over the gate, and reacting the contact material with the gate to form a silicide contact on the gate and consume at least one-half of the gate. By consuming such a large amount of the gate, a relatively thin gate can be converted into an ultra-thin gate with a thickness on the order of 100 to 200 angstroms. Preferably, the bottom surface of the gate is essentially undoped before reacting the contact material with the gate, and reacting the contact material with the gate pushes a peak concentration of a dopant in the gate towards the substrate so that a heavy concentration of the dopant is pushed to the bottom surface of the gate without being pushed into the substrate.

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 semiconductor device and method of manufacture thereof is provided. According to one embodiment, a semiconductor device is formed by forming a trench within a substrate. An oxide layer is formed within the trench and portions of the oxide layer are removed to expose one or more portions of the substrate within the trench. A plurality of doped polysilicon pillars are formed within the trench. The doped polysilicon pillars include one or more active region pillars formed on the one or more exposed portions of the substrate.

Abstract: A method for forming a semiconductor device is provided. The method includes providing a substrate having a gate formed thereon. A first doped region is formed in the substrate. The first doped region extends a first distance from the gate. A second doped region is formed in the substrate. The second doped region extends a second distance from the gate. The first distance is less than the second distance. A semiconductor device includes a substrate, isolation structures defined in the substrate, and a gate disposed on the substrate between adjacent isolation structures. A first doped region is defined in the substrate proximate the gate. The first doped region extends a first distance from the gate. A second doped region is defined in the substrate proximate the gate. The second doped region extends a second distance from the gate. The first distance is less than the first distance.

Abstract: A method of making an IGFET using solid phase diffusion is disclosed. The method includes providing a device region in a semiconductor substrate, forming a gate insulator on the device region, forming a gate on the gate insulator, forming an insulating layer over the gate and the device region, forming a heavily doped diffusion source layer over the insulating layer, and driving a dopant from the diffusion source layer through the insulating layer into the gate and the device region by solid phase diffusion, thereby heavily doping the gate and forming a heavily doped source and drain in the device region. Preferably, the gate and diffusion source layer are polysilicon, the gate insulator and insulating layer are silicon dioxide, the dopant is boron or boron species, and the dopant provides essentially all P-type doping for the gate, source and drain, thereby providing shallow channel junctions and reducing or eliminating boron penetration from the gate into the substrate.

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 semiconductor integrated circuit having a multiple split gate is forming using a first polysilicon layer and a second polysilicon layer to form alternating first and second gate electrodes within an active area. The alternating gate electrodes are electrically isolated from one another by means of a gate insulating layer that is formed adjacent the side-walls of each firs gate electrode. Source and drain regions are formed adjacent the ends of the multiple split gate to define a channel region.

Abstract: A nitrogen implanted region formed substantially below and substantially adjacent to a source/drain region of an IGFET forms a liner to retard the diffusion of the source/drain dopant atoms during a subsequent heat treatment operation such as an annealing step. The nitrogen liner may be formed by implantation of nitrogen to a given depth before the implantation of source/drain dopant to a lesser depth. Nitrogen may also be introduced into regions of the IGFET channel region beneath the gate electrode for retarding subsequent lateral diffusion of the source/drain dopant. Such nitrogen introduction may be accomplished using one or more angled implantation steps, or may be accomplished by annealing an implanted nitrogen layer formed using a perpendicular implant aligned to the gate electrode. The liner may be formed on the drain side of the IGFET or on both source and drain side, and may be formed under a lightly-doped region or under a heavily-doped region of the drain and/or source.

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 IGFET with a gate electrode and insulative spacers in a trench is disclosed. The IGFET includes a trench with opposing sidewalls and a bottom surface in a semiconductor substrate, a gate insulator on the bottom surface, a gate electrode on the gate insulator, and insulative spacers between the gate electrode and the sidewalls.

Abstract: An IGFET with elevated source and drain regions in close proximity to a gate with sloped sidewalls is disclosed. A method of making the IGFET includes forming a lower gate level over a semiconductor substrate, wherein the lower gate level includes a top surface, a bottom surface and sloped opposing sidewalls, and the top surface has a substantially greater length than the bottom surface, and depositing a semiconducting layer on the lower gate level and on underlying source and drain regions of the semiconductor substrate to form an upper gate level on the lower gate level, an elevated source region on the underlying source region, and an elevated drain region on the underlying drain region. The elevated source and drain regions are separated from the lower gate level due to a retrograde slope of the sidewalls of the lower gate level, and the elevated source and drain regions are separated from the upper gate level due to a lack of step coverage in the semiconducting layer.

Abstract: A dielectric interlayer is formed over a semiconductor substrate comprising at least one active region. The exposed upper surface of the dielectric interlayer is treated with nitrogen to form a nitrided barrier layer thereon. At least one hydrogen-containing dielectric layer is formed over the dielectric interlayer having the nitrided barrier layer thereon. The nitrided barrier layer serves as a barrier to diffusion of hydrogen from the at least one hydrogen-containing dielectric layer into the dielectric interlayer, thereby preventing a decrease in hot carrier injection reliability.

Abstract: An IGFET with metal spacers is disclosed. The IGFET includes a gate electrode on a gate insulator on a semiconductor substrate. Sidewall insulators are adjacent to opposing vertical edges of the gate electrode, and metal spacers are formed on the substrate and adjacent to the sidewall insulators. The metal spacers are electrically isolated from the gate electrode but contact portions of the drain and the source. Preferably, the metal spacers are adjacent to edges of the gate insulator beneath the sidewall insulators. The metal spacers are formed by depositing a metal layer over the substrate then applying an anisotropic etch. In one embodiment, the metal spacers contact lightly and heavily doped drain and source regions, thereby increasing the conductivity between the heavily doped drain and source regions and the channel underlying the gate electrode. The metal spacers can also provide low resistance drain and source contacts.

Abstract: A method is provided for obtaining a topography with a substantially planar upper surface. The profile of the upper surface of the semiconductor topography is first detected by a profile detection tool, such as a stylus profilometer. The profile detection tool creates a database to quantify the elevational variations across the upper surface of the semiconductor topography. The database is then provided to a control system of a deposition tool. The control system controls the deposition of a profile layer upon the upper surface of the semiconductor topography such that a thickness of the profile layer is a function of the elevation of the surface. In one embodiment, the control system controls a potential gradient across the semiconductor topography so as to cause more reactant species to be directed toward the more recessed regions of the topography. In another embodiment, the control system controls the opening and closing of valves disposed within a shower head above the semiconductor topography.

Abstract: An optical monitoring of electrical characteristics of devices in a semiconductor is performed during an anneal step to detect the time annealing is complete and activation occurs. A surface photovoltage measurement is made during annealing to monitor the charge state on the surface of a substrate wafer to determine when the substrate is fully annealed. The surface photovoltage measurement is monitored, the time of annealing is detected, and a selected over-anneal is controlled. The surface photovoltage (SPV) measurement is performed to determine a point at which a dopant or impurity such as boron or phosphorus is annealed in a silicon lattice. In some embodiments, the point of detection is used as a feedback signal in an RTA annealing system to adjust a bank of annealing lamps for annealing and activation uniformity control. The point of detection is also used to terminate the annealing process to minimize D.sub.t.

Abstract: A semiconductor process in which a first silicide is formed on silicon upper surfaces upon which a second silicide is selectively deposited. A refractory metal is blanket deposited on a semiconductor substrate. The semiconductor substrate is then heated to a first temperature to react portions of the refractory metal above the exposed silicon surfaces to form a first phase of a first silicide. The unreacted portions of the refractory metal then remove, typically with a wet etch process. The semiconductor substrate is then heated to a second temperature to form a second phase of the first silicide. The second temperature is typically greater than the first, and the resistivity of the second phase is less than a resistivity of the first phase. Thereafter, a second metal silicide is selectively deposited on the first silicide, preferably through the use of a chemical vapor deposition process.