| Patent application number | Description | Published |
|---|
| 20090011371 | REFLECTIVE FILM INTERFACE TO RESTORE TRANSVERSE MAGNETIC WAVE CONTRAST IN LITHOGRAPHIC PROCESSING - A method and system for exposing a resist layer with regions of photosensitivity to an image in a lithographic process using a high numerical aperture imaging tool. There is employed a substrate having thereover a layer reflective to the imaging tool radiation and a resist layer having a region of photosensitivity over the reflective layer, with the resist layer having a thickness. The imaging tool is adapted to project radiation containing an aerial image onto the resist layer, with a portion of the radiation containing the aerial image passing through the resist layer and reflecting back to the resist layer. The reflected radiation forms an interference pattern in the resist layer of the projected aerial image through the resist layer thickness. The thickness and location of the resist layer region of photosensitivity with respect to the reflective layer are selected to include from within the interference pattern higher contrast portions of the interference pattern in the direction of the resist thickness, and to exclude lower contrast portions of the interference pattern in the resist thickness direction from said resist layer region of photosensitivity, to improve contrast of the aerial image in said resist layer region of photosensitivity. | 01-08-2009 |
| 20090021718 | Method, Computer Program, Apparatus and System Providing Printing for an Illumination Mask for Three-Dimensional Images - A method able to provide illumination source parameters for illumination of a lithographic mask in order to project a three-dimensional image into a resist system. Source intensities of incident beams are determined using a near linear program and responsive to an allowed range of variation. Computer program, apparatus and system are detailed and variations are described. | 01-22-2009 |
| 20090040486 | REFLECTIVE FILM INTERFACE TO RESTORE TRANSVERSE MAGNETIC WAVE CONTRAST IN LITHOGRAPHIC PROCESSING - A method and system for exposing a resist layer with regions of photosensitivity to an image in a lithographic process using a high numerical aperture imaging tool. There is employed a substrate having thereover a layer reflective to the imaging tool radiation and a resist layer having a region of photosensitivity over the reflective layer, with the resist layer having a thickness. The imaging tool is adapted to project radiation containing an aerial image onto the resist layer, with a portion of the radiation containing the aerial image passing through the resist layer and reflecting back to the resist layer. The reflected radiation forms an interference pattern in the resist layer of the projected aerial image through the resist layer thickness. The thickness and location of the resist layer region of photosensitivity with respect to the reflective layer are selected to include from within the interference pattern higher contrast portions of the interference pattern in the direction of the resist thickness, and to exclude lower contrast portions of the interference pattern in the resist thickness direction from said resist layer region of photosensitivity, to improve contrast of the aerial image in said resist layer region of photosensitivity. | 02-12-2009 |
| 20090123057 | Method and System for Obtaining Bounds on Process Parameters for OPC-Verification - 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. | 05-14-2009 |
| 20090180711 | RENDERING A MASK USING COARSE MASK REPRESENTATION - A method, system and computer program product for rendering a mask are disclosed. A method of rendering a mask may comprise: providing an initial mask design for a photolithographic process, the initial mask design including polygons; initially rendering the initial mask design as a coarse mask representation in a pixel based image calculation; identifying an overhang portion; and rendering the overhang portion using a set of subpixels whose artifacts from spatial-localization lie outside a practical resolution of a pseudo lens having a numerical aperture larger than that of a projection lens used in the photolithographic process; and updating the initial rendering based on the overhang portion rendering. | 07-16-2009 |
| 20090185740 | CALCULATING IMAGE INTENSITY OF MASK BY DECOMPOSING MANHATTAN POLYGON BASED ON PARALLEL EDGE - A method, system, computer program product and table lookup system for calculating image intensity for a mask used in integrated circuit processing are disclosed. A method may comprise: decomposing a Manhattan polygon of the mask into decomposed areas based on parallel edges of the Manhattan polygon along only one dimension; determining a convolution of each decomposed area based on a table lookup; determining a sum of coherent systems contribution of the Manhattan polygon based on the convolutions of the decomposed areas; and outputting the determined sum of coherent system contribution for analyzing the mask. | 07-23-2009 |
| 20090193387 | METHODOLOGY AND SYSTEM FOR DETERMINING NUMERICAL ERRORS IN PIXEL-BASED IMAGING SIMULATION IN DESIGNING LITHOGRAPHIC MASKS - 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. | 07-30-2009 |
| 20090199150 | Step-Walk Relaxation Method for Global Optimization of Masks - A set of candidate global optima is identified, one of which is a global solution for making a mask for printing a lithographic pattern. A solution space is formed from dominant joint eigenvectors that is constrained for bright and dark areas of the printed pattern. The solution space is mapped to identify regions each containing at most one local minimum intensity. For each selected region, stepped intensity contours are generated for intensity of the dark areas and stepped constraint surfaces are generated for a target exposure dose at an individual test point. An individual test point is stepped toward a lowest intensity contour along the stepped constraint surfaces of each selected region. Further lowering of the intensities of these points is also detailed, where possible in adjacent regions, to yield final test points. The set of candidate global optima is the final test points at their respective lowest intensity contour of the respective selected regions. | 08-06-2009 |
| 20090271757 | DATA CORRECTING HIERARCHICAL INTEGRATED CIRCUIT LAYOUT ACCOMMODATING COMPENSATE FOR LONG RANGE CRITICAL DIMENSION VARIATION - A solution for performing a data correction on a hierarchical integrated circuit layout is provided. A method includes: receiving a CD compensation map for the long range critical dimension variation prior to the data correction; grouping compensation amounts of the CD compensation into multiple compensation ranges; generating multiple target layers corresponding to the multiple compensation ranges; super-imposing a region of the CD compensation map having a compensation amount falling into a compensation range over a respective target layer to generate a target shape; performing the data correction on the layout to generate a data corrected layout; performing the data correction on the target shape separately to generate a data corrected target shape; and combining the data corrected layout and the data corrected target shape based on the CD compensation map. | 10-29-2009 |
| 20100003605 | SYSTEM AND METHOD FOR PROJECTION LITHOGRAPHY WITH IMMERSED IMAGE-ALIGNED DIFFRACTIVE ELEMENT - A novel system and method and computer program product for exposing a photoresist film with patterns of finer resolution than can physically be projected onto the film in an ordinary image formed at the same wavelength. A hologram structure containing a set of resolvable spatial frequencies is first formed above the photoresist film. If necessary the photoresist is then sensitized. An illuminating wavefront containing a second set of resolvable spatial frequencies is projected through the hologram, forming a new set of transmitted spatial frequencies that expose the photoresist. The transmitted spatial frequencies include sum frequencies of higher frequency than is present in the hologram or illuminating wavefront, increasing the resolution of the exposing pattern. These high spatial frequency transmitted waves can be evanescent, or they can propagate at a steeper obliquity in a higher index medium than is possible in a projected image. A further method is described for designing lithographic masks to fabricate the hologram and to project the illuminating wavefront. In other embodiments, a simple personalization based on Talbot fringes and plasmonic interference is performed. | 01-07-2010 |
| 20100153901 | Determining manufacturability of lithographic mask by reducing target edge pairs used in determining a manufacturing penalty of the lithographic mask - The manufacturability of a lithographic mask employed in fabricating instances of a semiconductor device is determined. Target edge pairs are selected from mask layout data of the lithographic mask to determine a manufacturing penalty in making the lithographic mask. The mask layout data includes polygons, where each polygon has edges, and where each target edge pair is defined by two of the edges of one or more of the polygons. The number of the target edge pairs is reduced to decrease computational volume in determining the manufacturing penalty in making the lithographic mask. The manufacturability of the lithographic mask, including the manufacturing penalty in making the lithographic mask, is determined based on the target edge pairs as reduced in number. The manufacturability of the lithographic mask is output. The manufacturability of the lithographic mask is dependent on the manufacturing penalty in making the lithographic mask. | 06-17-2010 |
| 20100153902 | DETERMINING MANUFACTURABILITY OF LITHOGRAPHIC MASK BY SELECTING TARGET EDGE PAIRS USED IN DETERMINING A MANUFACTURING PENALTY OF THE LITHOGRAPHIC MASK - The manufacturability of a lithographic mask employed in fabricating instances of a semiconductor device is determined. Target edges are selected from mask layout data of the lithographic mask. The mask layout data includes polygons distributed over cells, where each polygon has edges. The cells include a center cell, two vertical cells above and below the center cell, and two horizontal cells to the left and right of the center cell. Target edge pairs are selected for determining a manufacturing penalty in making the lithographic mask, in a manner that decreases the computational volume in determining the manufacturing penalty. The manufacturability of the lithographic mask, including the manufacturing penalty in making the lithographic mask, is determined based on the target edge pairs selected. The manufacturability of the lithographic mask is output. The manufacturability of the lithographic mask is dependent on the manufacturing penalty in making the lithographic mask. | 06-17-2010 |
| 20100153903 | DETERMINING MANUFACTURABILITY OF LITHOGRAPHIC MASK USING CONTINUOUS DERIVATIVES CHARACTERIZING THE MANUFACTURABILITY ON A CONTINUOUS SCALE - The manufacturability of a lithographic mask employed in fabricating instances of a semiconductor device is determined. Target edge pairs are selected from mask layout data of the lithographic mask, for determining a manufacturing penalty in making the lithographic mask. The mask layout data includes polygons, where each polygon has a number of edges. Each target edge pair is defined by two of the edges of one or more of the polygons. The manufacturability of the lithographic mask, including the manufacturing penalty in making the lithographic mask, is determined. Determining the manufacturing penalty is based on the target edge pairs as selected. Determining the manufacturability of the lithographic mask uses continuous derivatives characterizing the manufacturability of the lithographic mask on a continuous scale. The manufacturability of the lithographic mask is output. The manufacturability of the lithographic mask is dependent on the manufacturing penalty in making the lithographic mask. | 06-17-2010 |
| 20100175042 | EFFICIENT ISOTROPIC MODELING APPROACH TO INCORPORATE ELECTROMAGNETIC EFFECTS INTO LITHOGRAPHIC PROCESS SIMULATIONS - 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. | 07-08-2010 |
| 20100175043 | FAST AND ACCURATE METHOD TO SIMULATE INTERMEDIATE RANGE FLARE EFFECTS - 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 5λ/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. | 07-08-2010 |
| 20100281449 | Method For Forming Arbitrary Lithographic Wavefronts Using Standard Mask Technology - A desired set of diffracted waves using mask features whose transmissions are chosen from a set of supported values are generated. A representation of the mask as a set of polygonal elements is created. Constraints which require that the ratio of the spatial frequencies in the representation take on the amplitude ratios of the desired set of diffracted waves are defined. An optimization algorithm is used to adjust the transmission discontinuities at the edges of the polygons to substantial equality with the discontinuity values allowed by the set of supported transmissions while maintaining the constraints. | 11-04-2010 |
| 20110096313 | Constrained Optimization Of Lithographic Source Intensities Under Contingent Requirements - A method for illuminating a mask to project a desired image pattern into a photoactive material is described. The method includes receiving an image pattern. Determining a relationship between source pixels in a set of source pixels to desired intensities at one or more points in the image pattern is performed. Linear constraints are imposed on a set of intensity values based on one or more contingent intensity condition. The contingent intensity conditions include integer variables specifying contingent constraints. The method includes determining values of the set of intensity values in accordance with the linear constraints, using a constrained optimization algorithm. The set of intensity values represents intensities of a set of source pixels. The set of intensity values are output. Apparatus and computer readable storage media are also described. | 04-28-2011 |
