Patents Assigned to PDF Solutions
  • Publication number: 20080169466
    Abstract: A test cell for localizing defects includes a first active region, a second active region formed substantially parallel to the first active region, a third active region formed substantially parallel to the first and second active regions, a fourth active region formed between the first and second active regions, and a fifth active region formed between the second and third active regions. The fourth and fifth active regions are formed adjacent to opposite end portions of the second active region. The fourth and fifth active regions are also formed substantially perpendicular to the second active region.
    Type: Application
    Filed: December 14, 2007
    Publication date: July 17, 2008
    Applicant: PDF Solutions, Inc.
    Inventors: Brian Stine, Victor Kitch, Mark Zwald, Stefano Tonello
  • Patent number: 7395518
    Abstract: A test vehicle comprises at least one product layer having a east one product circuit pattern on the product layer, and one or more clone layers formed over the product layer (1902). The one or more clone layers include a plurality of structures, which may include clone test vehicle circuit patterns and/or clone test vehicle vias (1902). The presence of one or more defects (1904) in the one or more clone layers (1908) is an indicator of a tendency of the product circuit pattern to impact yield of a succeeding layer to be formed over the product circuit pattern in a product (1910).
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: July 1, 2008
    Assignee: PDF Solutions, Inc.
    Inventors: Dennis J. Ciplickas, Christopher Hess
  • Patent number: 7373625
    Abstract: A system and method for predicting yield of integrated circuits includes at least one type of characterization vehicle which incorporates at least one feature which is representative of at least one type of feature to be incorporated in the final integrated circuit product. The characterization vehicle is subjected to at least one of the process operations making up the fabrication cycle to be used in fabricating the integrated circuit product in order to produce a yield model. The yield model embodies a layout as defined by the characterization vehicle and preferably includes features which facilitate the gathering of electrical test data and testing of prototype sections at operating speeds. An extraction engine extracts predetermined layout attributes from a proposed product layout. Operating on the yield model, the extraction engine produces yield predictions as a function of layout attributes and broken down by layers or steps in the fabrication process.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: May 13, 2008
    Assignee: PDF Solutions, Inc.
    Inventors: Brian E. Stine, Christopher Hess, John Kibarian, Kimon Michaels, Joseph C. Davis, Purnendu K. Mozumder, Sherry F. Lee, Larg H. Weiland, Dennis J. Ciplickas, David M. Stashower
  • Patent number: 7356800
    Abstract: A system and method for predicting yield of integrated circuits includes at least one type of characterization vehicle which incorporates at least one feature which is representative of at least one type of feature to be incorporated in the final integrated circuit product. The characterization vehicle is subjected to at least one of the process operations making up the fabrication cycle to be used in fabricating the integrated circuit product in order to produce a yield model. The yield model embodies a layout as defined by the characterization vehicle and preferably includes features which facilitate the gathering of electrical test data and testing of prototype sections at operating speeds. An extraction engine extracts predetermined layout attributes from a proposed product layout. Operating on the yield model, the extraction engine produces yield predictions as a function of layout attributes and broken down by layers or steps in the fabrication process.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: April 8, 2008
    Assignee: PDF Solutions, Inc.
    Inventors: Brian E. Stine, Christopher Hess, John Kibarian, Kimon Michaels, Joseph C. Davis, Purnendu K. Mozumder, Sherry F. Lee, Larg H. Weiland, Dennis J. Ciplickas, David M. Stashower
  • Patent number: 7348594
    Abstract: A test structure comprising a test pattern is formed on a substrate. The test pattern includes a first comb structure having a plurality of tines, and a second structure. The second structure may be a snake structure having a plurality of side walls or a second comb structure having a plurality of side walls. The tines of the first comb structure are positioned within side walls of the snake structure or second comb structure. The tines of the first comb structure are offset from a center of the side walls. Test data collected from the test structure are analyzed, to estimate product yield. The test structure may have a lower layer pattern, such that topographical variations of the lower layer pattern propagate to an upper layer pattern of the test structure.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: March 25, 2008
    Assignee: PDF Solutions, Inc.
    Inventors: Dennis J. Ciplickas, Brian E. Stine, Yanwen Fei
  • Publication number: 20080067446
    Abstract: Optimized dose assignments are determined for each portion of a layout by utilizing an improved proximity function and additional dose correction functions in performing a short range proximity effect correction. The optimized dose assignments are determined to minimize critical dimension (CD) deviations and maintain CD linearity across different feature sizes. The improved proximity function and additional dose correction functions are determined by calibration based on experimental CD measurements of test designs. The improved proximity function includes a sum of more than two Gaussian functions, each having an associated effect range and an associated weight, wherein one or more of the associated weights may be negative. The additional dose correction functions include an iso-dense bias correction function and a dose evaluation point displacement function for line end shortening correction.
    Type: Application
    Filed: June 22, 2006
    Publication date: March 20, 2008
    Applicant: PDF Solutions, Inc.
    Inventors: Nikola Belic, Hans Eisenmann
  • Patent number: 7334205
    Abstract: A method of optimizing production of semiconductor devices on a wafer comprises steps of characterizing at least one effect of at least one manufacturing component on at least one optimization criterion; inputting user optimization data; and, based on the at least one effect and the user optimization data, performing optimization to determine a layout of semiconductor devices on the wafer that optimizes performance according to the user optimization data.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: February 19, 2008
    Assignee: PDF Solutions, Inc.
    Inventor: Eitan Cadouri
  • Patent number: 7305638
    Abstract: A method for improving yield of a process for fabricating a read-only memory (ROM) includes evaluating a yield of a ROM fabrication process associated with a first ROM design. At least two candidate ROM design modifications are identified. At least one of the candidate ROM design modifications comprises inversion of bit values of data to be stored in the ROM. A plurality of criteria are applied, including at least an amount of yield improvement and a difficulty of implementation associated with each candidate ROM design modification. One of the candidate ROM design modifications is selected based on the application of the criteria. A modified ROM fabrication process is performed to fabricate a ROM according to the selected ROM design modification.
    Type: Grant
    Filed: May 13, 2005
    Date of Patent: December 4, 2007
    Assignee: PDF Solutions, Inc.
    Inventor: Brian E. Stine
  • Publication number: 20070268731
    Abstract: For methods of creating pluralities of semiconductor test structure layouts from a graphical specification, systems include a GUI to draw objects representing shapes of such layout, and to parameterize those objects to size and interrelate those objects. The GUI supports placement of cells in hierarchical layers. The graphical specification is parsed into an ASCII descriptor file from which node information is extracted and connection information among nodes preserved in separate graphs for an X direction and a Y direction of the layout. That node and connection information is further processed to obtain equations having variables (parameters) that relate points in the layout a defined point, and those equations used in forming source code that can be executed with values for the variables in the source code.
    Type: Application
    Filed: May 22, 2006
    Publication date: November 22, 2007
    Applicant: PDF Solutions, Inc.
    Inventors: Larg H. Weiland, Stefan Drapatz, Markus R. Decker
  • Patent number: 7278118
    Abstract: The invention provides a method and process for designing an integrated circuit based on using the results from both 1) a specific set of silicon test structure characterizations and 2) the decomposition of logic into combinations of simple logic primitives, from which a set of logic bricks are derived that can be assembled for a manufacturable-by-construction design. This implementation of logic is compatible with the lithography settings that are used for implementation of the memory blocks and other components on the integrated circuit, particularly by implementing geometrically consistent component features. The invention provides the ability to recompile a design comprised of logic and memory blocks onto a new geometry fabric to implement a set of technology-specific design changes, without requiring a complete redesign of the entire integrated circuit.
    Type: Grant
    Filed: November 4, 2005
    Date of Patent: October 2, 2007
    Assignee: PDF Solutions, Inc.
    Inventors: Lawrence T. Pileggi, Andrzej J. Strojwas, Lucio L. Lanza
  • Publication number: 20070118242
    Abstract: A system and method for predicting yield of integrated circuits includes at least one type of characterization vehicle which incorporates at least one feature which is representative of at least one type of feature to be incorporated in the final integrated circuit product. The characterization vehicle is subjected to at least one of the process operations making up the fabrication cycle to be used in fabricating the integrated circuit product in order to produce a yield model. The yield model embodies a layout as defined by the characterization vehicle and preferably includes features which facilitate the gathering of electrical test data and testing of prototype sections at operating speeds. An extraction engine extracts predetermined layout attributes from a proposed product layout. Operating on the yield model, the extraction engine produces yield predictions as a function of layout attributes and broken down by layers or steps in the fabrication process.
    Type: Application
    Filed: August 10, 2006
    Publication date: May 24, 2007
    Applicant: PDF Solutions, Inc.
    Inventors: Brian Stine, Christopher Hess, John Kibarian, Kimon Michaels, Joseph Davis, Purnendu Mozumder, Sherry Lee, Larg Weiland, Dennis Ciplickas, David Stashower
  • Patent number: 7220605
    Abstract: Dice on a wafer are selected to be tested using a yield map. The yield map incorporates yield information of different products produced by the same fabrication process. A die placement for a product to be produced by the same process is determined based on the yield map. An expected yield for a die in the die placement is also determined based on the yield map. The expected yield for the die is then used to determine whether to test the die.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: May 22, 2007
    Assignee: PDF Solutions, Inc.
    Inventor: Eitan Cadouri
  • Publication number: 20070105273
    Abstract: A die placement of dice to be formed on a semiconductor wafer is adjusted by obtaining a die placement and one or more locations on the wafer contacted by one or more processing structures or a substance emitted by one or more processing structures. The die placement is adjusted based on the obtained one or more locations on the wafer.
    Type: Application
    Filed: December 22, 2006
    Publication date: May 10, 2007
    Applicant: PDF Solutions, Inc.
    Inventor: Eitan Cadouri
  • Publication number: 20070075718
    Abstract: A layout for devices under test formed on a semiconductor wafer for use in wafer testing includes a first array of devices under test and a first pad set formed adjacent to the first array. The first pad set includes a gate force pad, a source pad, and a drain pad. Each of the devices under test in the first array is connected to the gate pad of the first pad set. Each of the devices under test in the first array is connected to the source pad of the first pad set. Each of the devices under test in the first array is connected to the drain pad of the first pad set.
    Type: Application
    Filed: October 3, 2005
    Publication date: April 5, 2007
    Applicant: PDF Solutions, Inc.
    Inventors: Christopher Hess, Angelo Rossoni, Stefano Tonello, Michele Squicciarini, Michele Quarantelli
  • Patent number: 7197726
    Abstract: A test structure combines a first structure (1010) for erosion evaluation with a second structure (1000) for extraction of defect size distributions. The first structure (1010) is a loop structure usable determine a resistance value that varies with metal height. The second structure is a NEST structure (1000). Loop lines of the loop structure (1010) are connected on both sides of the NEST structure (1000).
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: March 27, 2007
    Assignee: PDF Solutions, Inc.
    Inventors: Dennis J. Ciplickas, Markus Decker, Christopher Hess, Brian E. Stine, Larg H. Weiland
  • Patent number: 7190183
    Abstract: A die placement of dies on a wafer is selected to reduce test time of the dies by obtaining a die placement and determining placements of a tester head needed to test the dies in the die placement. A number of touchdowns needed in the determined placements of the tester head is determined, where a touchdown involves lowering the tester head to form an electrical contact between pins on the tester head and bonding pads on a die being tested. The die placement is adjusted to reduce the number of touchdowns.
    Type: Grant
    Filed: March 12, 2004
    Date of Patent: March 13, 2007
    Assignee: PDF Solutions, Inc.
    Inventor: Eitan Cadouri
  • Patent number: 7174521
    Abstract: A system and method for predicting yield of integrated circuits includes at least one type of characterization vehicle which incorporates at least one feature which is representative of at least one type of feature to be incorporated in the final integrated circuit product. The characterization vehicle is subjected to at least one of the process operations making up the fabrication cycle to be used in fabricating the integrated circuit product in order to produce a yield model. The yield model embodies a layout as defined by the characterization vehicle and preferably includes features which facilitate the gathering of electrical test data and testing of prototype sections at operating speeds. An extraction engine extracts predetermined layout attributes from a proposed product layout. Operating on the yield model, the extraction engine produces yield predictions as a function of layout attributes and broken down by layers or steps in the fabrication process.
    Type: Grant
    Filed: March 10, 2005
    Date of Patent: February 6, 2007
    Assignee: PDF Solutions, Inc.
    Inventors: Brian E. Stine, Christopher Hess, John Kibarian, Kimon Michaels, Joseph C. Davis, Purnendu K. Mozumder, Sherry F. Lee, Larg H. Weiland, Dennis J. Ciplickas, David M. Stashower
  • Patent number: 7169638
    Abstract: A die placement of dice to be formed on a semiconductor wafer is adjusted by obtaining a die placement and one or more locations on the wafer contacted by one or more processing structures or a substance emitted by one or more processing structures. The die placement is adjusted based on the obtained one or more locations on the wafer.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: January 30, 2007
    Assignee: PDF Solutions, Inc.
    Inventor: Eitan Cadouri
  • Patent number: 7154115
    Abstract: A test vehicle (100) comprises a substrate (99), a plurality of nested serpentine lines (202) on the substrate, and a plurality of test pads (204) on the substrate. Each serpentine line has a plurality of turn sections that comprise two parallel line segments connected by a perpendicular line segment. Each of the plurality of test pads is connected to a respective turn section of a respective one of the nested serpentine lines. Each pair of test pads connected to one of the subset of the nested serpentine lines has at least a respectively different turn section portion connected therebetween.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: December 26, 2006
    Assignee: PDF Solutions, Inc.
    Inventors: Brian E. Stine, Christopher Hess, Larg H. Weiland, Dennis J. Ciplickas
  • Publication number: 20060277506
    Abstract: A system and method for predicting yield of integrated circuits includes at least one type of characterization vehicle which incorporates at least one feature which is representative of at least one type of feature to be incorporated in the final integrated circuit product. The characterization vehicle is subjected to at least one of the process operations making up the fabrication cycle to be used in fabricating the integrated circuit product in order to produce a yield model. The yield model embodies a layout as defined by the characterization vehicle and preferably includes features which facilitate the gathering of electrical test data and testing of prototype sections at operating speeds. An extraction engine extracts predetermined layout attributes from a proposed product layout. Operating on the yield model, the extraction engine produces yield predictions as a function of layout attributes and broken down by layers or steps in the fabrication process.
    Type: Application
    Filed: August 10, 2006
    Publication date: December 7, 2006
    Applicant: PDF Solutions, Inc.
    Inventors: Brian Stine, Christopher Hess, John Kibarian, Kimon Michaels, Joseph Davis, Purnendu Mozumder, Sherry Lee, Larg Weiland, Dennis Ciplickas, David Stashower