Patent application number | Description | Published |
20090003073 | Rd Algorithm Improvement for Nrom Technology - Selecting a read voltage level for a NVM cell by using an initial value for the read voltage and performing a read operation, comparing an actual number of bits found to an expected number of bits and, if there is a discrepancy between the actual number and the expected number, adjusting the read voltage level, based on variable data such as statistics available, level occupation, neighbor level, previous chunks data, and other data used during read, program or erase. For example, based on a number of missing bits, or upon a result of a previous read operation, or a result obtained at another program level, or upon how many times the memory cell has been cycled, or upon how many memory cells are at each program level, or on a number of bits at another program level in a selected chunk of memory. | 01-01-2009 |
20090231915 | Reading array cell with matched reference cell - A method for reading a bit of a memory cell in a non-volatile memory (NVM) cell array, the method comprising providing a memory cell comprising a bit to be read and at least one other bit not to be read, and reading the bit to be read with respect to a multi-bit reference cell, the reference cell comprising a first bit at a first non-ground programmed state and a second bit at a second non-ground programmed state. Compared with the prior art, the present invention may enable achieving an improved sensing accuracy together with improved read disturb immunity. | 09-17-2009 |
20120029856 | METHOD AND SYSTEM FOR PROVIDING PROCESS TOOL CORRECTABLES - The present invention may include performing a first measurement process on a wafer of a lot of wafers, wherein the first measurement process includes measuring one or more characteristics of a plurality of targets distributed across one or more fields of the wafer, determining a set of process tool correctables for a residual larger than a selected threshold level utilizing a loss function, wherein the loss function is configured to fit a model for one or more process tools, as a function of field position, to one or more of the measured characteristics of the plurality of targets, wherein the set of process tool correctables includes one or more parameters of the model that act to minimize the difference between a norm of the residual and the selected threshold, and utilizing the determined process tool correctables to monitor or adjust one or more processes of the process tools. | 02-02-2012 |
20120033215 | MULTI-LAYER OVERLAY METROLOGY TARGET AND COMPLIMENTARY OVERLAY METROLOGY MEASUREMENT SYSTEMS - A multi-layer overlay target for use in imaging based metrology is disclosed. The overlay target includes a plurality of target structures including three or more target structures, each target structure including a set of two or more pattern elements, wherein the target structures are configured to share a common center of symmetry upon alignment of the target structures, each target structure being invariant to N degree rotation about the common center of symmetry, wherein N is equal to or greater than 180 degrees, wherein each of the two or more pattern elements has an individual center of symmetry, wherein each of the two or more pattern elements of each target structure is invariant to M degree rotation about the individual center of symmetry, wherein M is equal to or greater than 180 degrees. | 02-09-2012 |
20120084041 | METHOD AND SYSTEM FOR PROVIDING TOOL INDUCED SHIFT USING A SUB-SAMPLING SCHEME - The present invention may include measuring tool induced shift (TIS) on at least one wafer of a lot of wafers via an omniscient sampling process, randomly generating a plurality of sub-sampling schemes, each of the set of randomly generated sub-sampling schemes having the same number of sampled fields, measuring TIS at each location of each of the randomly generated sub-sampling schemes, approximating a set of TIS values for each of the randomly generated sub-sampling schemes utilizing the TIS measurements from each of the randomly generated sub-sampling schemes, wherein each set of TIS values for each of the randomly generated sub-sampling schemes is calculated utilizing an interpolation process configured to approximate a TIS value for each location not included in a randomly generated sub-sampling scheme, and determining a selected sub-sampling scheme by comparing each of the calculated sets of TIS values to the measured TIS of the omniscient sampling process. | 04-05-2012 |
20130035888 | METHOD AND SYSTEM FOR PROVIDING A QUALITY METRIC FOR IMPROVED PROCESS CONTROL - The present invention may include acquiring a plurality of overlay metrology measurement signals from a plurality of metrology targets distributed across one or more fields of a wafer of a lot of wafers, determining a plurality of overlay estimates for each of the plurality of overlay metrology measurement signals using a plurality of overlay algorithms, generating a plurality of overlay estimate distributions, and generating a first plurality of quality metrics utilizing the generated plurality of overlay estimate distributions, wherein each quality metric corresponds with one overlay estimate distribution of the generated plurality of overlay estimate distributions, each quality metric a function of a width of a corresponding generated overlay estimate distribution, each quality metric further being a function of asymmetry present in an overlay metrology measurement signal from an associated metrology target. | 02-07-2013 |
20130242305 | Imaging Overlay Metrology Target and Complimentary Overlay Metrology Measurement System - An exclusion region of interest imaging overlay target includes a self-symmetric target structure including two or more pattern elements, and an additional target structure including two or more pattern elements, wherein each of pattern elements of the additional target structure is contained within a boundary defined by one of the pattern elements of the self-symmetric target structure, wherein the self-symmetric target structure is characterized by a composite exterior region of interest, wherein the composite exterior region of interest is formed by removing two or more exclusion zones corresponding with the pattern elements of the additional target structure from an exterior region of interest encompassing the self-symmetric target structure, wherein each of the pattern elements of the additional target structure is characterized by an interior region of interest, wherein the self-symmetric target structure and the additional target structure are configured to have a common center of symmetry upon alignment. | 09-19-2013 |
20130293890 | Overlay Targets with Orthogonal Underlayer Dummyfill - The disclosure is directed to designing and using an overlay target with orthogonal underlayer dummyfill. According to various embodiments, an overlay target may include one or more segmented overlay pattern elements forming at least one overlay target structure. The overlay target may further include one or more inactive pattern elements forming at least one dummyfill target structure. Each of the one or more inactive pattern elements may include dummyfill segmented along an axis orthogonal to a segmentation axis of at least one proximately disposed overlay pattern element. In some embodiments, each of the target structures or layers may be formed from a separate process layer successively disposed upon a substrate, such as a silicon wafer. In some embodiments, the overlay and dummyfill target structures may be twofold or fourfold rotationally symmetric to allow for certain manufacturing or metrology advantages. | 11-07-2013 |