Abstract: A method for implementing systematic, variation-aware integrated circuit extraction includes inputting a set of processing conditions to a plurality of variation models, each model corresponding to a separate systematic, parametric variation associated with semiconductor manufacturing of an integrated circuit layout; generating, for each variation model, a netlist update attributable to the associated variation, wherein the netlist update is an update with respect to an original netlist extracted from the integrated circuit layout; and storing the netlist updates generated for each of the processing conditions.

Abstract: A method for forming a plurality of variable linewidth spacers adjoining a plurality of uniformly spaced topographic features uses a conformal resist layer upon a spacer material layer located over the plurality of uniformly spaced topographic features. The conformal resist layer is differentially exposed and developed to provide a differential thickness resist layer that is used as a sacrificial mask when forming the variable linewidth spacers. A method for forming uniform linewidth spacers adjoining narrowly spaced topographic features and widely spaced topographic features over the same substrate uses a masked isotropic etching of a variable thickness spacer material layer to provide a more uniform partially etched spacer material layer, followed by an unmasked anisotropic etching of the partially etched spacer material layer. A related method for forming the uniform linewidth spacers uses a two-step anisotropic etch method that includes at least one masking process step.

Abstract: IC chip design modeling using perimeter density to an electrical characteristic correlation is disclosed. In one embodiment, a method may include determining a perimeter density of conductive structure within each region of a plurality of regions of an integrated circuit (IC) chip design; correlating a measured electrical characteristic within a respective region of an IC chip that is based on the IC chip design to the perimeter density; and modeling the IC chip design based on the correlation.

Abstract: A method is provided for modeling lithographic processes in the design of photomasks for the manufacture of semiconductor integrated circuits, and more particularly for simulating intermediate range flare effects. For a region of influence (ROI) from first ROI1 of about 5?/NA to distance ROI2 when the point spread function has a slope that is slowly varying according to a predetermined criterion, then mask shapes at least within the distance range from ROI1 to ROI2 are smoothed prior to computing the SOCS convolutions. The method provides a fast method for simulating intermediate range flare effects with sufficient accuracy.

Abstract: A method of designing a layout for manufacturing an integrated circuit is provided, in which computationally intensive portions of the design process, such as simulation of an image transferred through a mask design, or simulation of electrical characteristics of a circuit, are performed more efficiently by only performing such computations on single instance of computational subunits that have an identical geometrical context. Thus, rather than performing such computations based on the functional layout, for which typical design process steps result in significant flattening of the functional hierarchy, and therefore increase the cost of computation, the invention performs simulations on computational subunits stored in a hierarchy based on geometrical context, which minimizes the cost of simulation. The resulting simulation results are subsequently assembled according to the functional layout.

Abstract: An iterative timing analysis is analytically performed before a chip is fabricated, based on a methodology using optical proximity correction techniques for shortening the gate lengths and adjusting metal line widths and proximity distances of critical time sensitive devices. The additional mask is used as a selective trim to form shortened gate lengths or wider metal lines for the selected, predetermined transistors, affecting the threshold voltages and the RC time constants of the selected devices. Marker shapes identify a predetermined subgroup of circuitry that constitutes the devices in the critical timing path. The analysis methodology is repeated as often as needed to improve the timing of the circuit with shortened designed gate lengths and modified RC timing constants until manufacturing limits are reached. A mask is made for the selected critical devices using OPC techniques.

Abstract: Disclosed are embodiments of forming an integrated circuit with a desired decoupling capacitance and with the uniform and targeted across-chip polysilicon perimeter density. The method includes laying out functional blocks to form the circuit according to the design and also laying out one or more decoupling capacitor blocks to achieve the desired decoupling capacitance. Then, local polysilicon perimeter densities of the blocks are determined and, as necessary, the decoupling capacitor blocks are reconfigured in order to adjust for differences in the local polysilicon perimeter densities. This reconfiguring is performed in a manner that essentially maintains the desired decoupling capacitance. Due to the across-chip polysilicon perimeter density uniformity, functional devices in different regions of the chip will exhibit limited performance parameter variations (e.g., limited threshold voltage variations).

Abstract: Disclosed is a method of laying out individual cells of an integrated circuit design, based at least in part on the known polysilicon perimeter densities of those cells. That is, the method embodiments use the knowledge of polysilicon perimeter density for known cells to drive placement of those cells on a chip (i.e., to drive floor-planning). The method embodiments can be used to achieve approximately uniform across-chip polysilicon perimeter density and, thereby to limit performance parameter variations between functional devices that are attributable to variations in polysilicon perimeter density. Alternatively, the method embodiments can be used to selectively control variations in the average polysilicon perimeter density of different regions of a chip and, thereby to selectively control certain performance parameter variations between functional devices located in those different regions.

Abstract: A method of integrated circuit (IC) design, an IC design system and computer program product therefore, e.g., for L3GO designs. Special case cells are cells that represent specialized, process dependent components and are provided as dual representation cells with an internal view and external view. The external view is high level abstract representation that includes access pins, boundary and possible blocking shapes/layers and optionally, parameterizations. Each external view includes cell to cell spacing rules and connecting and blocking/keepout rules for placement and routing. The internal cell or, internal view includes regular shapes forming cell components and defining cell construction details and are ground rule clean by construction or verified by simulation or hardware.

Abstract: IC chip design modeling using perimeter density to an electrical characteristic correlation is disclosed. In one embodiment, a method may include determining a perimeter density of conductive structure within each region of a plurality of regions of an integrated circuit (IC) chip design; correlating a measured electrical characteristic within a respective region of an IC chip that is based on the IC chip design to the perimeter density; and modeling the IC chip design based on the correlation.

Abstract: A design system for designing complex integrated circuits (ICs), a method of IC design and program product therefor. A layout unit receives a circuit description representing portions in a grid and glyph format. A checking unit checks grid and glyph portions of the design. An elaboration unit generates a target layout from the checked design. A data prep unit prepares the target layout for mask making. A pattern caching unit selectively replaces portions of the design with previously cached results for improved design efficiency.

Abstract: An approach that provides electrically driven optical proximity correction is described. In one embodiment, there is a method for performing an electrically driven optical proximity correction. In this embodiment, an integrated circuit mask layout representative of a plurality of layered shapes each defined by features and edges is received. A lithography simulation is run on the mask layout. An electrical characteristic is extracted from the output of the lithography simulation for each layer of the mask layout. A determination as to whether the extracted electrical characteristic is in conformance with a target electrical characteristic is made. Edges of the plurality of layered shapes in the mask layout are adjusted in response to determining that the extracted electrical characteristic for a layer in the mask layout fails to conform with the target electrical characteristic.

Abstract: A method is provided for designing a mask that includes the use of a pixel-based simulation of a lithographic process model, in which test structures are designed for determining numerical and discretization errors associated with the pixel grid as opposed to other model inaccuracies. The test structure has a plurality of rows of the same sequence of features, but each row is offset from other rows along an x-direction by a multiple of a minimum step size, such as used in modifying masks during optical proximity correction. The images for each row are simulated with a lithographic model that uses the selected pixel-grid size and the differences between row images are compared. If the differences between rows exceed or violate a predetermined criterion, the pixel grid size may be modified to minimize discretization and/or numerical errors due to the choice of pixel grid size.

Abstract: A method, system and computer program product for verifying printability of a mask layout for a photolithographic process are disclosed. A simulation of the photolithographic process for the designed mask layout is simulated using a simplified version of the mask layout with a lower accuracy to generate a lower accuracy simulated image. Where the lower accuracy simulated image is determined as potentially including an error, a further simulation of the designated portion of the mask layout with a higher accuracy will be performed.

Abstract: A design system for designing complex integrated circuits (ICs), a method of IC design and program product therefor. A layout unit receives a circuit description representing portions in a grid and glyph format. A checking unit checks grid and glyph portions of the design. An elaboration unit generates a target layout from the checked design. A data prep unit prepares the target layout for mask making. A pattern caching unit selectively replaces portions of the design with previously cached results for improved design efficiency.

Abstract: A method is provided for designing a mask layout for an integrated circuit that ensures proper functional interaction among circuit features by including functional inter-layer and intra-layer constraints on the wafer. The functional constraints used according to the present invention are applied among the simulated wafer images to ensure proper functional interaction, while relaxing or eliminating the EPE constraints on the location of the wafer images.

Abstract: Impact on parametric performance of physical design choices for transistors is scored for on-current and off-current of the transistors. The impact of the design parameters are incorporated into parameters that measure predicted shift in mean on-current and mean off-current and parameters that measure predicted increase in deviations in the distribution of on-current and the off-current. Statistics may be taken at a cell level, a block level, or a chip level to optimize a chip design in a design phase, or to predict changes in parametric yield during manufacturing or after a depressed parametric yield is observed. Further, parametric yield and current level may be predicted region by region and compared with observed thermal emission to pinpoint any anomaly region in a chip to facilitate detection and correction in any mistakes in chip design.

Abstract: A method is provided for designing a mask layout for an integrated circuit that ensures proper functional interaction among circuit features by including functional inter-layer and intra-layer constraints on the wafer. The functional constraints used according to the present invention are applied among the simulated wafer images to ensure proper functional interaction, while relaxing or eliminating the EPE constraints on the location of the wafer images.

Abstract: A method of forming a planar CMOS transistor divides the step of forming the gate layer into a first step of patterning a resist layer with a first portion of the gate layer pattern and then etching the polysilicon with the pattern of the gates. A second step patterns a second resist layer with the image of the gate pads and local interconnect and then etching the polysilicon with the pattern of the gate pads and local interconnect, thereby reducing the number of diffraction and other cross-talk from different exposed areas.

Abstract: A mask inspection method and system. Provided is a mask fabrication database describing geometrical shapes S to be printed as part of a mask pattern on a reticle to fabricate a mask through use of a mask fabrication tooling. The shapes S appear on the mask as shapes S? upon being printed. At least one of the shapes S? may be geometrically distorted relative to a corresponding at least one of the shapes S due to a lack of precision in the mask fabrication tooling. Also provided is a mask inspection database to be used for inspecting the mask after the mask has been fabricated by the mask fabrication tooling. The mask inspection database describes shapes S? approximating the shapes S?. A geometric distortion between the shapes S? and S? is less than a corresponding geometric distortion between the shapes S? and S.