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Lars W. Liebmann, Poughquag US

Lars W. Liebmann, Poughquag, NY US

Patent application numberDescriptionPublished
20080244503System for Coloring a Partially Colored Design in an Alternating Phase Shift Mask - A method of designing an alternating phase shifting mask for projecting an image of an integrated circuit design. Phase units are binary colorable within each unit of the hierarchical circuit design, e.g., cell, an array, a net, or array of nets and/or cells, the phase shapes. The assignment of phases or colors within a hierarchical unit will be correctly binary colored to satisfy the lithographic, manufacturability and other design rules, referred to collectively as coloring rules. During assembly with other units, the coloring of phases in a hierarchical unit may change (e.g., be reversed or flipped), but the correct binary colorability of a hierarchical unit is preserved, which simplifies assembly of the integrated circuit layout.10-02-2008
20090037866ALTERNATING PHASE SHIFT MASK OPTIMIZATION FOR IMPROVED PROCESS WINDOW - A method for designing alternating phase shift masks is provided, in which narrow phase shapes located between densely spaced design shapes are colored to allow a maximum amount of light transmission. After assigning and ensuring binary legalization of the phase shapes, the narrow phase shapes are assigned a color, such as 0° phase shift, that allows the more light transmission than the alternate or opposite color (e.g. 180° phase shift), which helps avoid printing errors such as resist scumming between closely spaced shapes, and maximizes the lithographic process window.02-05-2009
20090199151ELECTRICALLY DRIVEN OPTICAL PROXIMITY CORRECTION - 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.08-06-2009
20090204930IPHYSICAL DESIGN SYSTEM AND METHOD - 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.08-13-2009
20090290401PLACEMENT AND OPTIMIZATION OF PROCESS DUMMY CELLS - A method for laying out process dummy cells in relationship to inside memory cells of a memory array includes (a) calculating an initial process performance parameter for the memory array; (b) changing dummy cell layout configuration for a layer electrically connected to inside cells; (c) applying lithographic simulation and yield model for both the inside memory cells and the changed layout configuration process dummy cells; and (d) repeating steps (b) and (c) until yield is maximized. Checks may be performed to ensure that there is enough room to make the change and that there is no significant adverse effect to neighboring circuits. The process performance parameter may be yield or a process window for the inside memory cells.11-26-2009
20100017780DIFFERENTIAL ALTERNATING PHASE SHIFT MASK OPTIMIZATION - A method of designing a mask for projecting an image of an integrated circuit design in lithographic processing, wherein the integrated circuit layout has a plurality of segments of critical width. The method comprises creating a first mask design by aligning mask features used to assist in projecting critical width segments with the critical width segments of the integrated circuit design, such that the first mask design meets predetermined manufacturability design rules, and creating a second mask design by aligning mask features with the critical width segments of the integrated circuit design, such that the second mask design meets predetermined lithographic design rules in regions local to the critical width segments. The method then includes identifying design features of the second mask design that violate the predetermined manufacturability design rules, and then creating a third mask design derived from the second mask design wherein the mask features of the second mask design that violate the predetermined manufacturability rules are selectively replaced by mask features from the first mask design so that the third mask design meets the predetermined manufacturability design rules. By way of example, the mask features used to assist in projecting critical width segments may comprise alternating phase shifting regions or sub-resolution assist features.01-21-2010
20100122231ELECTRICALLY-DRIVEN OPTICAL PROXIMITY CORRECTION TO COMPENSATE FOR NON-OPTICAL EFFECTS - A contour of a mask design for an integrated circuit is modified to compensate for systematic variations arising from non-optical effects such as stress, well proximity, rapid thermal anneal, or spacer thickness. Electrical characteristics of a simulated integrated circuit chip fabricated using the mask design are extracted and compared to design specifications, and one or more edges of the contour are adjusted to reduce the systematic variation until the electrical characteristic is within specification. The particular electrical characteristic preferably depends on which layer is to be fabricated from the mask: on-current for a polysilicon; resistance for contact; resistance and capacitance for metal; current for active; and resistance for vias. For systematic threshold voltage variation, the contour is adjusted to match a gate length which corresponds to an on-current value according to pre-calculated curves for contour current and gate length at a nominal threshold voltage of the chip.05-13-2010

Patent applications by Lars W. Liebmann, Poughquag, NY US