摘要:
The present invention relates to the modeling of lithographic processes for use in the design of photomasks for the manufacture of semiconductor integrated circuits, and particularly to the modeling of the complex effects due to interaction of the illuminating light with the mask topography. According to the invention, an isofield perturbation to a thin mask representation of the mask is provided by determining, for the components of the illumination, differences between the electric field on a feature edge having finite thickness and on the corresponding feature edge of a thin mask representation. An isofield perturbation is obtained from a weighted coherent combination of the differences for each illumination polarization. The electric field of a mask having topographic edges is represented by combining a thin mask representation with the isofield perturbation applied to each edge of the mask.
摘要:
A method of conveying the designer's intended electrical characteristics for a semiconductor design is provided by forming tolerance bands for a design layer of interest that take into consideration constraints from design layers that interact with and influence the features on the design layer of interest. The method determines regions, i.e. tolerance bands, within which the printed edges of features of the layer of interest will print within a predetermined criterion, and satisfy a variety of constraints, including, but not limited to, electrical, overlay and manufacturability constraints arising from the influence of features on other layers. The method may be implemented in a computer program product for execution on a computer system. The resulting tolerance bands can be used to efficiently convey the designer's intent to a lithographer, an OPC engineer or a mask manufacturer or tool.
摘要:
A method of designing a layout of an alternating phase shifting mask for projecting an image of an integrated circuit design having a plurality of features to be projected using alternating phase shifting segments, including a gate-shrink region of a transistor having a critical width along a length thereof that extends beyond a diffusion region. The method also provides alternating phase shift design rules based on alternating phase shift design parameters comprising minimum phase width, minimum phase-to-phase spacing, and minimum extension of critical width beyond another feature. The method then includes identifying portions of the integrated circuit layout having a critical width feature that violate the alternating phase shift design rules, and reducing the length that the critical width gate-shrink region feature extends beyond the other diffusion region feature to the minimum extension. An alternating phase shifting mask layout is then generated in conformance with the alternating phase shift design rules.
摘要:
A method for designing a mask for fabricating an integrated circuit is provided wherein a mask layout that requires coloring, such as for alternating phase shift, double-exposure and double-exposure-etch masks, is organized into uncolored hierarchical design units. Prior to modification by OPC, each hierarchical design unit is locally colored. OPC is then performed on the locally colored hierarchical design unit. The local coloring information for the hierarchically arranged OPC-modified design unit may be discarded. After OPC modification, the uncolored OPC-modified design units may be placed within the mask layout, and the flattened data may be colored. Thus, turnaround time for mask design is significantly improved since the numerically intensive OPC is performed on the hierarchical data, avoiding the need to perform OPC on flattened data, whereas the less intensive global coloring is performed on flattened data.
摘要:
A method of conveying the designer's intended electrical characteristics for a semiconductor design is provided by forming tolerance bands for a design layer of interest that take into consideration constraints from design layers that interact with and influence the features on the design layer of interest. The method determines regions, i.e. tolerance bands, within which the printed edges of features of the layer of interest will print within a predetermined criterion, and satisfy a variety of constraints, including, but not limited to, electrical, overlay and manufacturability constraints arising from the influence of features on other layers. The method may be implemented in a computer program product for execution on a computer system. The resulting tolerance bands can be used to efficiently convey the designer's intent to a lithographer, an OPC engineer or a mask manufacturer or tool.
摘要:
A method and computer program product is described for optimizing the design of a circuit layout that assigns binary properties to the design elements according to a hierarchy of rules. For example, the design of an alternating phase shifted mask (altPSM) is optimized first according to rules that assign phase shapes that maximize image quality for critical circuit elements, and then further optimized to minimize mask manufacturability problems without significantly increasing the complexity of the design process flow. Further optimization of the design according to additional rules can be performed in a sequentially decreasing priority order. As the priority of rules decrease, some violation of lower priority rules may be acceptable, as long as higher priority rules are not violated.
摘要:
A method for predicting functionality of an integrated circuit segment to be lithographically printed on a wafer. Initially there is provided a two-dimensional design of an integrated circuit, including an integrated circuit segment having critical width, and a two-dimensional printed image of the critical width integrated circuit segment is simulated. The method then includes determining a ratio of perimeters or areas of the designed critical width integrated circuit segment to the simulated printed critical width integrated circuit segment, and predicting functionality of the critical width integrated circuit segment after printing based on the ratio of perimeters or areas.
摘要:
Embodiments of the present invention provide a method of performing printability verification of a mask layout. The method includes creating one or more tight clusters; computing a set of process parameters associated with a point on said mask; comparing said set of process parameters to said one or more tight clusters; and reporting an error when at least one of said process parameters is away from said one or more tight clusters.
摘要:
A method for designing a mask for fabricating an integrated circuit is provided wherein a mask layout that requires coloring, such as for alternating phase shift, double-exposure and double-exposure-etch masks, is organized into uncolored hierarchical design units. Prior to modification by OPC, each hierarchical design unit is locally colored. OPC is then performed on the locally colored hierarchical design unit. The local coloring information for the hierarchically arranged OPC-modified design unit may be discarded. After OPC modification, the uncolored OPC-modified design units may be placed within the mask layout, and the flattened data may be colored. Thus, turnaround time for mask design is significantly improved since the numerically intensive OPC is performed on the hierarchical data, avoiding the need to perform OPC on flattened data, whereas the less intensive global coloring is performed on flattened data.
摘要:
A method for predicting functionality of an integrated circuit segment to be lithographically printed on a wafer. Initially there is provided a two-dimensional design of an integrated circuit, including an integrated circuit segment having critical width, and a two-dimensional printed image of the critical width integrated circuit segment is simulated. The method then includes determining a ratio of perimeters or areas of the designed critical width integrated circuit segment to the simulated printed critical width integrated circuit segment, and predicting functionality of the critical width integrated circuit segment after printing based on the ratio of perimeters or areas.