Abstract: A reticle that is within specifications is inspected so as to generate a baseline event indicating a location and a size value for each unusual reticle feature. After using the reticle in photolithography, the reticle is inspected so as to generate a current event indicating a location and a size value for each unusual reticle feature. An inspection report of candidate defects and their images is generated so that these candidate defects include a first subset of the current events and their corresponding candidate defect images and exclude a second subset of the current events and their corresponding excluded images. Each of the first included events has a location and size value that fails to match any baseline event's location and size value, and each of the excluded second events has a location and size value that matches a baseline event's location and size value.

Abstract: An EUV integrated circuit fabrication method and system EUV that includes blank inspection, defect characterization, simulation, pattern compensation, modification of the mask writer database, inspection and simulation of patterned masks, and patterned mask repair. The system performs blank inspection to identify defects at multiple focal planes within the blank. The mask can be relocated on the blank and alterations to the pattern can be developed to compensate for the defects prior to prior to patterning the mask. Once the mask has been patterned, the reticle is inspected to identify any additional or remaining defects that were not picked up during blank inspection or fully mitigated through pattern compensation. The patterned reticle can then be repaired prior to integrated circuit fabrication.

Abstract: Provided are novel methods and systems for inspecting photomasks to identify lithographically significant contamination defects. Inspection may be performed without a separate reference image provided from a database or another die. Inspection techniques described herein involve capturing one or more test images of a photomask and constructing corresponding test “simulation” images using specific lithographic and/or resist models. These test simulation images simulate printable and/or resist patterns of the inspected photomask. Furthermore, the initial test images are used in parallel operations to generate “synthetic” images. These images represent a defect-free photomask pattern. The synthetic images are then used for generating reference simulation images, which are similar to the test simulation images but are free from lithographically significant contamination defects.

Abstract: An EUV integrated circuit fabrication method and system EUV that includes blank inspection, defect characterization, simulation, pattern compensation, modification of the mask writer database, inspection and simulation of patterned masks, and patterned mask repair. The system performs blank inspection to identify defects at multiple focal planes within the blank. The mask can be relocated on the blank and alterations to the pattern can be developed to compensate for the defects prior to prior to patterning the mask. Once the mask has been patterned, the reticle is inspected to identify any additional or remaining defects that were not picked up during blank inspection or fully mitigated through pattern compensation. The patterned reticle can then be repaired prior to integrated circuit fabrication.

Abstract: Methods and systems for classifying defects detected on a reticle are provided. One method includes determining an impact that a defect detected on a reticle will have on the performance of a device being fabricated on a wafer based on how at least a portion of the reticle prints or will print on the wafer. The defect is located in the portion of the reticle. The method also includes assigning a classification to the defect based on the impact.

Abstract: Various computer-implemented methods are provided. One method for generating a process for inspecting reticle layout data includes identifying a first region in the reticle layout data. A printability of the first region is more sensitive to changes in process parameters than a printability of a second region in the reticle layout data. The method also includes assigning one or more inspection parameters to the first region and the second region such that the first region will be inspected during the process with a higher sensitivity than the second region. Another method includes inspecting the first region with a higher sensitivity than the second region. An additional method includes simulating how the reticle layout data will print. Simulation of the first and second regions is performed with one or more different simulation parameters such that the first region is simulated with a higher fidelity than the second region.

Abstract: Methods and apparatus relating to the inspection of photomasks are described. In an embodiment, detection of thin line or sub-resolution assist features may be used for selective sensitivity during photomask inspection. Other embodiments are also described.

Abstract: Provided are novel methods and systems for inspecting photomasks to identify lithographically significant contamination defects. Inspection may be performed without a separate reference image provided from a database or another die. Inspection techniques described herein involve capturing one or more test images of a photomask and constructing corresponding test “simulation” images using specific lithographic and/or resist models. These test simulation images simulate printable and/or resist patterns of the inspected photomask. Furthermore, the initial test images are used in parallel operations to generate “synthetic” images. These images represent a defect-free photomask pattern. The synthetic images are then used for generating reference simulation images, which are similar to the test simulation images but are free from lithographically significant contamination defects.

Abstract: A method and tool for generating reconstructed images that model the high NA effects of a lithography tool used to image patterns produced by a mask. Comparison of the reconstructed images with reference images characterize the mask. The method involves providing a mask reticle for inspection. Generating matrix values associated with a high NA corrective filter matrix that characterizes a high NA lithography system used to print from the mask. Illuminating the mask to produce a patterned illumination beam that is filtered with filters associated with the high NA corrective filter matrix elements to obtain a plurality of filtered beams that include raw image data that is processed to obtain a reconstructed image that is further processed and compared with reference images to obtain mask characterization information.

Abstract: Disclosed are methods and apparatus for inspecting a sub-resolution assist features (SRAF) on a reticle. A test flux measurement for a boundary area that encompasses a width and a length portion of a test SRAF is determined, and at least one reference flux measurement for one or more boundary areas of one or more reference SRAF's is determined. The test flux measurement is compared with the reference flux measurements. The comparison is used to then determine whether the test SRAF is undersized or oversized. If the test SRAF is determined to be oversized, it may then be determined whether the test SRAF is defective based on the comparison using a first threshold.

Abstract: The invention is directed to droplet actuator devices and assay methods. The method may include, among other things, a method of conducting enzymatic assays using umbelliferone substrates with cyclodextrins in droplets in oil, the method including incubating a droplet in oil, the droplet preferably comprising an umbelliferone substrate, a sample, and a cyclodextrin compound. The methods may further include a method of substantially eliminating cross-contamination between droplets in enzymatic containing substrate-based bioassays. The method may include immobilization of the enzymatic substrate including forming an inclusion complex with the substrate for stabilizing the substrate within an aqueous environment, wherein the inclusion complex may be formed using cyclodextrins. In yet another embodiment, the invention may provide a method of enhancing hydrolysis of enzymatic substrates.

Abstract: A method for selecting a set of features for monitoring a lithography process using a reticle, by identifying a set of candidate features, defining control regions around the candidate features, performing substrate level analysis using the reticle with different settings for the lithography process, determining which of the candidate features are most changed by the different settings, ranking the candidate features according to how much they are changed, and selecting the test set of features from those candidate features that are most changed.

Abstract: A method for identifying lithographically significant defects. A photomask is illuminated to produce images that experience different parameters of the reticle as imaged by an inspection tool. Example parameters include a transmission intensity image and a reflection intensity image. The images are processed together to recover a band limited mask pattern associated with the photomask. A model of an exposure lithography system for chip fabrication is adapted to accommodate the band limited mask pattern as an input which is input into the model to obtain an aerial image of the mask pattern that is processed with a photoresist model yielding a resist-modeled image. The resist-modeled image is used to determine if the photomask has lithographically significant defects.

Abstract: Methods for detecting and classifying defects on a reticle are provided. One method includes acquiring images of the reticle at first and second conditions during inspection of the reticle. The first condition is different than the second condition. The method also includes detecting the defects on the reticle using one or more of the images acquired at the first condition. In addition, the method includes classifying an importance of the defects detected on the reticle using one or more of the images acquired at the second condition. The detecting and classifying steps are performed substantially simultaneously during the inspection.

Abstract: Computer-implemented methods for detecting defects in reticle design data are provided. One method includes generating a first simulated image illustrating how the reticle design data will be printed on a reticle using a reticle manufacturing process. The method also includes generating second simulated images using the first simulated image. The second simulated images illustrate how the reticle will be printed on a wafer at different values of one or more parameters of a wafer printing process. The method further includes detecting defects in the reticle design data using the second simulated images. Another method includes the generating steps described above in addition to determining a rate of change in a characteristic of the second simulated images as a function of the different values. This method also includes detecting defects in the reticle design data based on the rate of change.

Abstract: Disclosed are methods and apparatus for inspecting a sub-resolution assist features (SRAF) on a reticle. A test flux measurement for a boundary area that encompasses a width and a length portion of a test SRAF is determined, and at least one reference flux measurement for one or more boundary areas of one or more reference SRAF's is determined. The test flux measurement is compared with the reference flux measurements. The comparison is used to then determine whether the test SRAF is undersized or oversized.

Abstract: Methods for detecting and classifying defects on a reticle are provided. One method includes acquiring images of the reticle at first and second conditions during inspection of the reticle. The first condition is different than the second condition. The method also includes detecting the defects on the reticle using one or more of the images acquired at the first condition. In addition, the method includes classifying an importance of the defects detected on the reticle using one or more of the images acquired at the second condition. The detecting and classifying steps are performed substantially simultaneously during the inspection.

Abstract: Disclosed are techniques and apparatus for accounting for differing levels of defect susceptibility in different pattern areas of a reticle in an inspection of such reticle or in inspection of a semiconductor device fabricated from such reticle. In general terms, two or more areas of a reticle are analyzed to quantify each area's susceptibility to defects on the final semiconductor product. That is, each reticle area is analyzed and given a quantified defect susceptibility value, such as a MEEF (mask error enhancement factor) value. Such analysis includes analysis of an image that is estimated to result from the lithography tool which is to be utilized to expose semiconductor devices with the reticle. The defect susceptibility value generally depends on the reticle area's density and whether the correspond area of the estimated lithography image has intensity values which are proximate to an exposure threshold for a particular resist material to be used on the final semiconductor device.

Abstract: A method for identifying lithographically significant defects. A photomask is illuminated to produce images that experience different parameters of the reticle as imaged by an inspection tool. Example parameters include a transmission intensity image and a reflection intensity image. The images are processed together to recover a band limited mask pattern associated with the photomask. A model of an exposure lithography system for chip fabrication is adapted to accommodate the band limited mask pattern as an input which is input into the model to obtain an aerial image of the mask pattern that is processed with a photoresist model yielding a resist-modeled image. The resist-modeled image is used to determine if the photomask has lithographically significant defects.

Abstract: A method and tool for generating reconstructed images that model the high NA effects of a lithography tool used to image patterns produced by a mask. Comparison of the reconstructed images with reference images characterize the mask. The method involves providing a mask reticle for inspection. Generating matrix values associated with a high NA corrective filter matrix that characterizes a high NA lithography system used to print from the mask. Illuminating the mask to produce a patterned illumination beam that is filtered with filters associated with the high NA corrective filter matrix elements to obtain a plurality of filtered beams that include raw image data that is processed to obtain a reconstructed image that is further processed and compared with reference images to obtain mask characterization information.