| Patent application number | Description | Published |
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| 20100115486 | ASSIST FEATURE PLACEMENT BASED ON A FOCUS-SENSITIVE COST-COVARIANCE FIELD - One embodiment of the present invention provides a system that determines an assist feature placement within a post-optical proximity correction (post-OPC) mask layout. During operation, the system receives a set of target patterns which represent a set of polygons in a pre-OPC mask layout. The system then constructs a focus-sensitive cost function based on the target patterns, wherein the focus-sensitive cost function represents an amount of movement of post-OPC contours of the target patterns in response to changes in focus condition of the lithography system. Note that the contours of the target patterns substantially coincide with the edges of set of the polygons. Next, the system computes a cost-covariance field (CCF field) based on the focus-sensitive cost function, wherein the CCF field is a two-dimensional (2D) map representing changes to the focus-sensitive cost function due to an addition of a pattern at a given location within the post-OPC mask layout. Finally, the system generates assist features for the post-OPC mask layout based on the CCF field. | 05-06-2010 |
| 20100199255 | METHOD AND APPARATUS FOR CORRECTING ASSIST-FEATURE-PRINTING ERRORS IN A LAYOUT - One embodiment of the present invention provides a system that adjusts assist features in a layout to prevent assist features from printing. During operation, the system receives a layout. The system then identifies an assist-feature (AF)-printing hotspot in the layout, wherein the AF-printing hotspot includes a set of assist features and one or more target patterns in proximity to the set of assist features. At least one assist feature in the set of assist features is expected to print during a lithography process. Next, the system modifies the AF-printing hotspot by: (1) modifying the set of assist features; and (2) performing optical-proximity-correction (OPC) on the one or more target patterns. The system then performs a lithography simulation on the modified AF-printing hotspot to determine if: (1) a through-process-window associated with the modified AF-printing hotspot is acceptable; and (2) no assist feature in the modified set of assist features is expected to print. If so, the system replaces the AF-printing hotspot with the modified AF-printing hotspot. | 08-05-2010 |
| 20100262946 | Model-based assist feature placement using inverse imaging approach - Some embodiments provide techniques and systems to identify locations in a target mask layout for placing assist features. During operation, an embodiment can determine a spatial sampling frequency to sample the target mask layout, wherein sampling the target mask layout at the spatial sampling frequency prevents spatial aliasing in a gradient of a cost function which is used for computing an inverse mask field. Next, the system can generate a grayscale image by sampling the target mask layout at the spatial sampling frequency. The system can then compute the inverse mask field by iteratively modifying the grayscale image. The system can use the gradient of the cost function to guide the iterative modification process. Next, the system can filter the inverse mask field using a morphological operator, and use the filtered inverse mask field to identify assist feature locations in the target mask layout. | 10-14-2010 |
| 20110202891 | EVALUATING THE QUALITY OF AN ASSIST FEATURE PLACEMENT BASED ON A FOCUS-SENSITIVE COST-COVARIANCE FIELD - One embodiment of the present invention provides a system that determines an assist feature placement within a post-optical proximity correction (post-OPC) mask layout. During operation, the system receives a set of target patterns which represent a set of polygons in a pre-OPC mask layout. The system then constructs a focus-sensitive cost function based on the target patterns, wherein the focus-sensitive cost function represents an amount of movement of post-OPC contours of the target patterns in response to changes in focus condition of the lithography system. Note that the contours of the target patterns substantially coincide with the edges of set of the polygons. Next, the system computes a cost-covariance field (CCF field) based on the focus-sensitive cost function, wherein the CCF field is a two-dimensional (2D) map representing changes to the focus-sensitive cost function due to an addition of a pattern at a given location within the post-OPC mask layout. Finally, the system generates assist features for the post-OPC mask layout based on the CCF field. | 08-18-2011 |
| Patent application number | Description | Published |
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| 20090003487 | REDUCING AMPLITUDE MODULATED NOISE FOR A WIRELESS TRANSCEIVER - Mechanisms for reducing amplitude-modulated noise in a wireless transceiver are generally described. In one example, an apparatus includes a radio-frequency identification (RFID) transceiver, a digital-analog converter (DAC) coupled with the transceiver, a reconstruction filter coupled with the digital-analog converter, and hold logic associated with the reconstruction filter to enable the reconstruction filter to hold its output voltage. | 01-01-2009 |
| 20090085748 | MITIGATING PROCESSING LATENCY IN RFID EXCHANGES - In a radio frequency identification (RFID) system that requires an RFID reader to receive a response from an RFID tag and then transmit a command to the RFID tag within a certain time period, the RFID reader may place an initial part of the command transmission in the RFID reader's transmit chain before receiving the entire response from the RFID tag, and complete the command transmission after receiving the entire response. | 04-02-2009 |
| 20100250834 | METHOD AND SYSTEM TO PERFORM CACHING BASED ON FILE-LEVEL HEURISTICS - A method and system to perform caching based at least on one or more file-level heuristics. The caching of a storage medium in a caching device is performed by a cache policy engine. The cache policy engine receives file-level information of input/output access of data of the storage medium and caches or evicts the data of the storage medium in the caching device based on the received file-level information. By utilizing information about the files and file operations associated with the disk sectors or logical block addresses of the storage medium, the cache policy engine can make a better decision on the data selection of the storage medium to be cached in or evicted from the caching device in one embodiment of the invention. Higher cache hit rates can be achieved and the performance of the system utilizing the cache policy engine is improved. | 09-30-2010 |
