摘要:
A method is disclosed for providing associated shapes of an optical lithography mask in relation to predetermined main shapes of the mask. The method includes generating simplified layout patterns from the predetermined main shapes of the mask. Such layout patterns are generated by eliminating detail of the main shapes which leads to unmanufacturable associated shapes while preserving geometrically relevant shape information. The associated shapes are then generated relative to the simplified mask patterns.
摘要:
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.
摘要:
A method is disclosed for providing associated shapes of an optical lithography mask in relation to predetermined main shapes of the mask. The method includes generating simplified layout patterns from the predetermined main shapes of the mask. Such layout patterns are generated by eliminating detail of the main shapes which leads to unmanufacturable associated shapes while preserving geometrically relevant shape information. The associated shapes are then generated relative to the simplified mask patterns.
摘要:
Methods, and program storage devices, for performing model-based optical proximity correction by providing a region of interest (ROI) having an interaction distance and locating at least one polygon within the ROI. A cut line of sample points representative of a set of vertices, or plurality of cut lines, are generated within the ROI across at least one lateral edge of the polygon(s). An angular position, and first and second portions of the cut line residing on opposing sides of an intersection between the cut line and the lateral edge of the polygon are determined, followed by generating a new ROI by extending the original ROI beyond its interaction distance based on such angular position, and first and second portions of the cut line. In this manner, a variety of new ROIs may be generated, in a variety of different directions, to ultimately correct for optical proximity.
摘要:
Disclosed is a method of locating systematic defects in integrated circuits. The invention first performs a preliminary extracting and index processing of the circuit design and then performs feature searching. When performing the preliminary extracting and index processing the invention establishes a window grid for the circuit design and merges basis patterns with shapes in the circuit design within each window of the window grid. The invention transforms shapes in a each window into feature vectors by finding intersections between the basis patterns and the shapes in the windows. Then, the invention clusters the feature vectors to produce an index of feature vectors. After performing the extracting and index processing, the invention performs the process of feature searching by first identifying a defect region window of the circuit layout and similarly merging basis patterns with shapes in the defect region window. This merging process can include rotating and mirroring the shapes in the defect region. The invention similarly transforms shapes in the defect region window into defect vectors by finding intersections between basis patterns and the shapes in the defect region. Then, the invention can easily find feature vectors that are similar to the defect vector using, for example, representative feature vectors from the index of feature vectors. Then, the similarities and differences between the defect vectors and the feature vectors can be analyzed.
摘要:
A method of synthesizing layout patterns to test an optical proximity correction algorithm. The method comprises the steps of: embodying Walsh patterns in a set of Walsh pattern matrices; processing groups of matrices from the set of Walsh pattern matrices to form a set of test matrices; mapping the set of test matrices to a test pattern set.
摘要:
A method is described for performing model-based optical proximity corrections on a mask layout used in an optical lithography process having a plurality of mask shapes. Model-based optical proximity correction is performed by computing the image intensity on selected evaluation points on the mask layout. The image intensity to be computed includes optical flare and stray light effects due to the interactions between the shapes on the mask layout. The computation of the image intensity involves sub-dividing the mask layout into a plurality of regions, each region at an increasing distance from the evaluation point. The contributions of the optical flare and stray light effects due to mask shapes in each of the regions are then determined. Finally, all the contributions thus obtained are combined to obtain the final computation of the image intensity at the selected point.
摘要:
A method for calculating long-range image contributions from mask polygons. An algorithm is introduced having application to Optical Proximity Correction in optical lithography. A finite integral for each sector of a polygon replaces an infinite integral. Integrating over two triangles, rather than integrating on the full sector, achieves a finite integral. An analytical approach is presented for a power law kernel to reduce the numerical integration of a sector to an analytical expression evaluation. The mask polygon is divided into regions to calculate interaction effects, such as intermediate-range and long-range effects, by truncating the mask instead of truncating the kernel function.
摘要:
Methods, and a program storage device for executing such methods, for performing model-based optical proximity correction by providing a mask matrix having a region of interest (ROI) and locating a plurality of points of interest within the mask matrix. A first polygon having a number of vertices representative of the located points of interest is computed, followed by determining a spatial relation between its vertices and the ROI. The vertices of the first polygon are then pinned to boundaries of and within the ROI such that a second polygon is formed on the ROI. The process is repeated for all vertices of the first polygon such that the second polygon is collapsed onto the ROI. This collapsed second polygon is then used to correct for optical proximity.
摘要:
Disclosed is a method of locating systematic defects in integrated circuits. The invention first performs a preliminary extracting and index processing of the circuit design and then performs feature searching. When performing the preliminary extracting and index processing the invention establishes a window grid for the circuit design and merges basis patterns with shapes in the circuit design within each window of the window grid. The invention transforms shapes in a each window into feature vectors by finding intersections between the basis patterns and the shapes in the windows. Then, the invention clusters the feature vectors to produce an index of feature vectors. After performing the extracting and index processing, the invention performs the process of feature searching by first identifying a defect region window of the circuit layout and similarly merging basis patterns with shapes in the defect region window. This merging process can include rotating and mirroring the shapes in the defect region. The invention similarly transforms shapes in the defect region window into defect vectors by finding intersections between basis patterns and the shapes in the defect region. Then, the invention can easily find feature vectors that are similar to the defect vector using, for example, representative feature vectors from the index of feature vectors. Then, the similarities and differences between the defect vectors and the feature vectors can be analyzed.