50 results about "Resolution enhancement technologies" patented technology

One embodiment of the present invention provides a system that applies resolution enhancement techniques (RETs) selectively to a layout of an integrated circuit. Upon receiving the layout of the integrated circuit, the system identifies a plurality of critical regions within the layout based on an analysis of one or more of, timing, dynamic power, and off-state leakage current. The system then performs a first set of aggressive RET operations on the plurality of critical regions. The system also performs a second set of less aggressive RET operations on other non-critical regions of the layout.

The invention details methods and apparatus for a routing system or router that includes a model. The model can be in many different forms including but not limited to: resolution enhancement technologies such as OPC; lithography model including but not limited to aerial image; pattern-dependent functions; functions for timing / signal integrity / power; manufacturing process variations; and measured silicon data. In one embodiment, the model can be described as input to the system and the model calculator can interact either with the data structure or the query engine of the detail router or both. The model calculator can accept input as a set of geometry description and produce output to guide the query functions. An example technique called set intersection is disclosed herein to combine multiple models in the system. A preferred embodiment of this invention includes a full chip grid-based router being aware of manufacturability.

An optical lithography method is disclosed that uses double exposure of a reusable template mask and a trim mask to fabricate regularly-placed rectangular contacts in standard cells of application-specific integrated circuits (ASICs). A first exposure of the reusable template mask with periodic patterns forms periodic dark lines on a wafer and a second exposure of an application-specific trim mask remove the unwanted part of the dark lines and the small cuts of the dark lines left form the rectangular regularly-placed contacts. All contacts are placed regularly in one direction while unrestrictedly in the perpendicular direction. The regular placement of patterns on the template mask enable more effective use of resolution enhancement technologies, which in turn allows a decrease in manufacturing cost and the minimum contact size and pitch. Since there is no extra application-specific mask needed comparing with the conventional lithography method for unrestrictedly-placed contacts, the extra cost is kept to the lowest. The method of the invention can be used in the fabrication of standard cells in application-specific integrated circuits (ASICs) to improve circuit performance and decrease circuit area and manufacturing cost.

A multiple mask and a multiple masking layer technique can be used to pattern a single IC layer. A resolution enhancement technique can be used to define one or more fine-line patterns in a first masking layer, wherein each fine-line feature is sub-wavelength. Moreover, the pitch of each fine-line pattern is less than or equal to that wavelength. The portions of the fine-line features not needed to implement the circuit design are then removed or designated for removal using a mask. After patterning of the first masking layer, another mask can then be used to define coarse features in a second masking layer formed over the patterned first masking layer. At least one coarse feature is defined to connect two fine-line features. The IC layer can be patterned using the composite mask formed by the patterned first and second masking layers.

A multiple mask and a multiple masking layer technique can be used to pattern a single IC layer. A resolution enhancement technique can be used to define one or more fine-line patterns in a first masking layer, wherein each fine-line feature is sub-wavelength. Moreover, the pitch of each fine-line pattern is less than or equal to that wavelength. The portions of the fine-line features not needed to implement the circuit design are then removed or designated for removal using a mask. After patterning of the first masking layer, another mask can then be used to define coarse features in a second masking layer formed over the patterned first masking layer. At least one coarse feature is defined to connect two fine-line features. The IC layer can be patterned using the composite mask formed by the patterned first and second masking layers.

An architecture is described for digital multi-phase modulators (MPM) that leads to an efficient, high performance hardware realization. The combined modulator, switching phases and output filter can be viewed as a multi-level digital to analog converter with high power output, or a power D / A, and concepts used in D / A converters are leveraged to achieve high performance and hardware efficiency. The modulator can be split into three functional blocks including a decoder that determines how many phases are on at any time, a selector that determines which phases are on at any time, and a single high resolution module that is time shared among all phases. The resulting architecture scales favorably with a large number of phases, fs, facilitates fast update rates of the input command well above the single phase switching frequency and is compatible with a wide range of known DPWM techniques for the LSB module and resolution-enhancement techniques such as dithering or Σ-Δ modulation.

A contrast-based resolution enhancing technology (RET) determines a distribution of contrast values for edge fragments in a design layout or portion thereof. Resolution enhancement is applied to the edge fragments in a way that increases the number of edge fragments having a contrast value that exceeds a predetermined threshold.

A tool for optimizing the layout of a microdevice adds fragmentation points to polygons in a first hierarchical database layer in a manner suitable for application of a tool to apply a resolution enhancement technique (RET) such as optical and process correction (OPC). Portions of polygons in a database level that interact with polygons of a second level in the database are promoted to the second database level, and refragmented. The RET operates on the polygons of the first and second levels of the database to determine how polygons of each of the first and second levels should be adjusted, if necessary, such that the layout is optimized.

A method and apparatus for integrated circuit layout optimization are provided. In the conventional art, the major challenges in building integrated circuits (IC) at sub-wavelength geometries include i) to ensure the design intent is faithfully transferred onto silicon; ii) to ensure the design is manufacturable, or with acceptable yield subject to process variations. The present invention provides the method to process a layout database to optimize or correct or fix layout violations or enhancements. The layout violations are identified through various means such as design rules, recommended rules, timing / signal integrity / power constraints, lithography rules, Resolution Enhancement Technologies (RET) requirements and preferences, and process and manufacturing constraints. Particularly, the method, techniques and procedures of creating software tools of the present invention used to perform the layout violations or enhancements are disclosed.

A method of performing a resolution enhancement technique such as OPC on an initial layout description involves fragmenting a polygon that represents a feature to be created into a number of edge fragments. One or more of the edge fragments is assigned an initial simulation site at which the image intensity is calculated. Upon calculation of the image intensity, the position and / or number of initial simulation sites is varied. New calculations are made of the image intensity with the revised placement or number of simulation sites in order to calculate an OPC correction for the edge fragment. In other embodiments, fragmentation of a polygon is adjusted based on the image intensities calculated at the simulation sites. In one embodiment, the image intensity gradient vector calculated at the initial simulation sites is used to adjust the simulation sites and / or fragmentation of the polygon.

A contrast-based resolution enhancing technology (RET) determines a distribution of contrast values for edge fragments in a design layout or portion thereof. Resolution enhancement is applied to the edge fragments in a way that increases the number of edge fragments having a contrast value that exceeds a predetermined threshold.

A system for calculating mask data to create a desired layout pattern on a wafer reads all or a portion of a desired layout pattern. Mask data having pixels with transmission characteristics is defined along with corresponding optimal mask data pixel transmission characteristics. An objective function is defined having one or more penalty functions that promote solutions representing a desired resolution enhancement technique. Optimization of the objective function determines the transmission characteristics of the pixels in the mask data that is used to create one or more corresponding masks or reticles.

A contrast-based resolution enhancing technology (RET) determines a distribution of contrast values for edge fragments in a design layout or portion thereof. Resolution enhancement is applied to the edge fragments in a way that increases the number of edge fragments having a contrast value that exceeds a predetermined threshold.

A method of calculating process conditions for performing optical and process correction (OPC) or other resolution enhancement techniques on a layout design. Process conditions are estimated on a layout database on a substantially uniform grid. Contour curves are created from the estimated process conditions. The contour curves are then compared against the features in the layout to determine edge placement errors. From the edge placement errors, OPC or other corrections for the features can be made.

In one embodiment, a spacing is determined for each edge of a number of features in a photolithographic design. The edges have at least a partially predictable layout. Based on the spacing and the predictable layout, a bridge structure is generated. Each bridge of the bridge structure connects one of the edges to an edge of a neighboring feature. Then, the features and the bridge structure are provided for a phase assignment. The phase assignment assigns features at opposite ends of each bridge in the bridge structure to opposite phases. In another embodiment, a sub-resolution assist feature (SRAF) is introduced for an edge of a feature and a bridge is generated from the feature to the SRAF. Then, the feature and the SRAF are assigned to opposite phases based on the relationship defined by the bridge.

A method for compensating for optical distortions occurring in regions associated with non-phase-shifting regions in a mask or reticle. OPC or other resolution enhancement techniques are performed on one or more edge segments associated with adjacent phase-shifting regions in order to compensate for edge position errors occurring in areas corresponding to non-phase-shifting regions.

A system for calculating mask data to create a desired layout pattern on a wafer reads all or a portion of a desired layout pattern. Mask data having pixels with transmission characteristics is defined along with corresponding optimal mask data pixel transmission characteristics. An objective function is defined having one or more penalty functions that promote solutions representing a desired resolution enhancement technique. Optimization of the objective function determines the transmission characteristics of the pixels in the mask data that is used to create one or more corresponding masks or reticles.

A system and method for optimizing an illumination source to print a desired pattern of features dividing a light source into pixels and determining an optimum intensity for each pixel such that when the pixels are simultaneously illuminated, the error in a printed pattern of features is minimized. In one embodiment, pixel solutions are constrained from solutions that are bright, continuous, and smooth. In another embodiment, the light source optimization and resolution enhancement technique(s) are iteratively performed to minimize errors in a printed pattern of features.

A method for model-based verification of resolution enhancement techniques (RET) and optical proximity correction (OPC) in lithography includes scaling shapes of a drawn mask layout to their corresponding intended wafer dimensions so as to create a scaled image. A first feature of the scaled image is shifted with respect to a second feature thereof in accordance with a predetermined maximum overlay error. An intersection parameter of the first and said second features of the scaled image is calculated so as to determine a yield metric of an ideal layout. A first feature of a simulated wafer image is shifted with respect to a second feature thereof in accordance with the predetermined maximum overlay error. An intersection parameter of the first and said second features of the simulated wafer image is calculated so as to determine a yield metric of a simulated layout, and the yield metric of the simulated wafer image is compared to the yield metric of the scaled image.

A multiple mask and a multiple masking layer technique can be used to pattern a single IC layer. A resolution enhancement technique can be used to define one or more fine-line patterns in a first masking layer, wherein each fine-line feature is sub-wavelength. Moreover, the pitch of each fine-line pattern is less than or equal to that wavelength. The portions of the fine-line features not needed to implement the circuit design are then removed or designated for removal using a mask. After patterning of the first masking layer, another mask can then be used to define coarse features in a second masking layer formed over the patterned first masking layer. At least one coarse feature is defined to connect two fine-line features, wherein the coarse feature(s) can be derived from a desired layout using a shrink / grow operation. The IC layer can be patterned using the composite mask formed by the patterned first and second masking layers.

An image reversal method is described that removes the etch resistance requirement from a resist. A high resolution resist pattern comprised of islands, lines, or trenches is formed with a large process window by exposing through one or more masks including phase edge masks and optionally with resolution enhancement techniques. A complementary material replacement (CMR) layer comprised of an organic polymer or material such as fluorosilicate glass which has a lower etch rate than the resist is coated over the resist pattern. CMR and resist layers are etched simultaneously to provide an image reversed pattern in the CMR layer which is etch transferred into a substrate. The method avoids edge roughness like bird's beak defects in the etched pattern and is useful for applications including forming contact holes in dielectric layers, forming polysilicon gates, and forming trenches in a damascene process. It is also valuable for direct write methods where an image reversal scheme is desired.

A method and apparatus for compensating for flare intensity variations across an integrated circuit. A layout description for a physical layer of an integrated circuit or portion thereof is divided into a number of regions such as adjacent tiles. An estimate of the flare intensity in each region is determined. The flare intensity values calculated are divided into a number of ranges. In one embodiment, a data layer in a layout description is defined for each range of flare values computed. Features to be printed in an area having a flare value in a particular range are associated with a corresponding additional data layer. The features associated with each additional data layer are analyzed with a resolution enhancement technique that is selected or adjusted to compensate for differing flare values occurring in the integrated circuit.

A method for model-based verification of resolution enhancement techniques (RET) and optical proximity correction (OPC) in lithography, the method comprising: scaling the shape of a drawn mask layout to its corresponding intended wafer dimensions to generate a scaled image. The first feature thereof is offset relative to the second feature of the scale image according to a predetermined maximum overlay error. Intersection parameters of said first and said second features of said scale image are calculated to determine a yield measure of an ideal layout. The first feature thereof is offset relative to the second feature of the simulated wafer image according to the predetermined maximum overlay error. calculating an intersection parameter of said first and said second features of said simulated wafer image to determine a yield metric of a simulated layout, and comparing said yield metric of said simulated wafer image to said yield of said scaled image measure.