Inventors list

Assignees list

Classification tree browser

Top 100 Inventors

Top 100 Assignees


Kehan Tian, Poughkeepsie US

Kehan Tian, Poughkeepsie, NY US

Patent application numberDescriptionPublished
20090021718Method, 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
20090185740CALCULATING 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
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
20100153901Determining 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
20100153902DETERMINING 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
20100153903DETERMINING 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
20120008134METHOD TO MATCH EXPOSURE TOOLS USING A PROGRAMMABLE ILLUMINATOR - Programmable illuminators in exposure tools are employed to increase the degree of freedom in tool matching. A tool matching methodology is provided that utilizes the fine adjustment of the individual source pixel intensity based on a linear programming (LP) problem subjected to user-specific constraints to minimize the difference of the lithographic wafer data between two tools. The lithographic data can be critical dimension differences from multiple targets and multiple process conditions. This LP problem can be modified to include a binary variable for matching sources using multi-scan exposure. The method can be applied to scenarios that the reference tool is a physical tool or a virtual ideal tool. In addition, this method can match different lithography systems, each including a tool and a mask.01-12-2012
20120017194METHOD FOR FAST ESTIMATION OF LITHOGRAPHIC BINDING PATTERNS IN AN INTEGRATED CIRCUIT LAYOUT - The present invention provides a lithographic difficulty metric that is a function of an energy ratio factor that includes a ratio of hard-to-print energy to easy-to-print energy of the diffraction orders along an angular coordinate θ01-19-2012

Patent applications by Kehan Tian, Poughkeepsie, NY US