KLA-Tencor Patent Grants

Hybrid phase unwrapping systems and methods for patterned wafer measurement

Granted: April 25, 2017
Patent Number: 9632038
Systems and methods for unwrapping phase signals obtained from interferometry measurements of patterned wafer surfaces are disclosed. A phase unwrapping method in accordance with the present disclosure may calculate a front surface phase map and a back surface phase map of a wafer, subtract the back surface phase map from the front surface phase map to obtain a phase difference map, unwrap the phase difference map to obtain a wafer thickness variation map, unwrap the back surface phase…

Lens array-based illumination for wafer inspection

Granted: April 18, 2017
Patent Number: 9625726
Systems configured to provide illumination for wafer inspection performed by a wafer inspection tool are provided. One system includes one or more pupil lenses configured to focus a first far field pattern having a shape different than a shape of light generated by a light source. The system also includes a field lens array positioned between the one or more pupil lenses and an aperture stop. In addition, the system includes a lens group configured to focus a second far field pattern…

Source multiplexing illumination for mask inspection

Granted: April 18, 2017
Patent Number: 9625810
Methods and systems for source multiplexing illumination for mask inspection are disclosed. Such illumination systems enable EUV sources of small brightness to be used for EUV mask defect inspection at nodes below the 22 nm. Utilizing the multiple plane or conic mirrors that are either attached to a continuously rotating base with different angles or individually rotating to position for each pulse, the reflected beams may be directed through a common optical path. The light may then be…

Calculation method for local film stress measurements using local film thickness values

Granted: April 18, 2017
Patent Number: 9625823
A system and method for local film stress calculation is disclosed. The method may include specifying a plurality of measurement points on a substrate, the substrate being configured to receive a film deposition; obtaining a local film thickness measurement for each measurement point; obtaining a local wafer shape parameter for each measurement point; and calculating a local film stress value for each measurement point based on the local film thickness measurement and the local wafer…

Computation efficiency by diffraction order truncation

Granted: April 18, 2017
Patent Number: 9625937
A method for improving computation efficiency for diffraction signals in optical metrology is described. The method includes simulating a set of diffraction orders for a three-dimensional structure. The diffraction orders within the set of diffraction orders are then prioritized. The set of diffraction orders is truncated to provide a truncated set of diffraction orders based on the prioritizing. Finally, a simulated spectrum is provided based on the truncated set of diffraction orders.

Grazing order metrology

Granted: April 11, 2017
Patent Number: 9618448
Metrology targets, optical systems and methods are provided, which enable metrology measurements of very small features, using resonance of illuminated radiation within periodical structures of the target, under appropriate illumination. Metrology targets comprise periodical structure(s) configured to resonate incident radiation and having a pitch defined by the grating equation with respect to configured parameters such as the selected diffraction order, refractive indices and the…

End effectors and reticle handling at a high throughput

Granted: April 11, 2017
Patent Number: 9618857
End effectors of reticle mechanical interface pods as well as reticle handling methods are provided, which handle the reticle by the end effector by applying a lateral force and/or a downward force on the reticle during the handling to fixate the reticle to at least two supports (e.g., at least four fingers) which are attached to at least two arms of the end effector and are configured to apply an upwards force on the reticle. Hence the reticle is fixated to the end effector and can be…

Detecting defects on wafers based on 2D scatter plots of values determined for output generated using different optics modes

Granted: April 11, 2017
Patent Number: 9619876
Methods and systems for detecting defects on a wafer are provided. One method includes determining difference values for pixels in first output for a wafer generated using a first optics mode of an inspection system and determining other values for pixels in second output for the wafer generated using a second optics mode of the inspection system. The first and second optics modes are different from each other. The method also includes generating a two-dimensional scatter plot of the…

Inspecting high-resolution photolithography masks

Granted: April 11, 2017
Patent Number: 9619878
Optical inspection methods and apparatus for high-resolution photomasks using only a test image. A filter is applied to an image signal received from radiation that is transmitted by or reflected from a photomask having a test image. The filter may be implemented using programmed control to adjust and control filter conditions, illumination conditions, and magnification conditions.

Photomultiplier tube, image sensor, and an inspection system using a PMT or image sensor

Granted: April 11, 2017
Patent Number: 9620341
A system for inspecting a sample including a detector, either a photomultiplier tube or an electron-bombarded image sensor, that is positioned to receive light from the sample. The detector includes a semiconductor photocathode and a photodiode. Notably, the photodiode includes a p-doped semiconductor layer, an n-doped semiconductor layer formed on a first surface of the p-doped semiconductor layer to form a diode, and a pure boron layer formed on a second surface of the p-doped…

Position sensitive substrate device

Granted: April 11, 2017
Patent Number: 9620400
Some aspects of the present disclosure relate to a system having a substrate device, a substrate support surface, and a substrate handler that positions the substrate device on the substrate support surface. The substrate device and the substrate support surface may have counterpart coarse position units and fine position units. The system may measure coarse positional offsets between the first and second coarse position units, re-position the substrate device on the substrate support…

Method and system for providing process tool correctables using an optimized sampling scheme with smart interpolation

Granted: April 11, 2017
Patent Number: 9620426
The present invention may include performing a first measurement on a wafer of a first lot of wafers via an omniscient sampling process, calculating a first set of process tool correctables utilizing one or more results of the measurement performed via an omniscient sampling process, randomly selecting a set of field sampling locations of the wafer of a first lot of wafers, calculating a second set of process tool correctables by applying an interpolation process to the randomly selected…

Image sensor, an inspection system and a method of inspecting an article

Granted: April 11, 2017
Patent Number: 9620547
A high sensitivity image sensor comprises an epitaxial layer of silicon that is intrinsic or lightly p doped (such as a doping level less than about 1013 cm?3). CMOS or CCD circuits are fabricated on the front-side of the epitaxial layer. Epitaxial p and n type layers are grown on the backside of the epitaxial layer. A pure boron layer is deposited on the n-type epitaxial layer. Some boron is driven a few nm into the n-type epitaxial layer from the backside during the boron deposition…

Apparatus and methods for detecting defects in vertical memory

Granted: April 4, 2017
Patent Number: 9612209
Disclosed are methods and apparatus for inspecting a vertical memory stack. On an inspection tool, incident light having a first wavelength range is used to detect defects on a surface of the vertical memory stack. On the inspection tool, incident light having a second wavelength range is used to detect defects on both the surface and throughout a depth of the vertical memory stack. The defects detected using the first and second wavelength range are compared to detect defects only…

Qualifying patterns for microlithography

Granted: April 4, 2017
Patent Number: 9612541
Disclosed are methods and apparatus for qualifying a photolithographic reticle. A reticle inspection tool is used to acquire at least two images at different imaging configurations from each pattern area of the reticle. A reticle pattern is reconstructed based on each at least two images from each pattern area of the reticle. For each reconstructed reticle pattern, a lithographic process with two or more different process conditions is modeled on such reconstructed reticle pattern to…

Image processing architecture

Granted: April 4, 2017
Patent Number: 9613391
An inspection system that receives image data corresponding to an image and processes the image data to produce a report corresponding to characteristics of the image. Interface cards receive the image data in a flow, where each interface card receives image data corresponding to a different portion of the image. Process nodes connect to the interface cards, and receive the image data from the interface cards. A host computer is connected to the process nodes, and job managers…

Creating defect classifiers and nuisance filters

Granted: April 4, 2017
Patent Number: 9613411
Methods and systems for setting up a classifier for defects detected on a wafer are provided. One method includes generating a template for a defect classifier for defects detected on a wafer and applying the template to a training data set. The training data set includes information for defects detected on the wafer or another wafer. The method also includes determining one or more parameters for the defect classifier based on results of the applying step.

System and method for inhibiting radiative emission of a laser-sustained plasma source

Granted: April 4, 2017
Patent Number: 9615439
A system for forming a laser-sustained plasma includes a gas containment element, an illumination source configured to generate pump illumination, and a collector element. The gas containment element is configured to contain a volume of a gas mixture. The collector element is configured to focus the pump illumination from the pumping source into the volume of the gas mixture contained within the gas containment element in order to generate a plasma within the volume of the gas mixture…

Method and system for providing tool induced shift using a sub-sampling scheme

Granted: March 28, 2017
Patent Number: 9606453
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…

Accurate and fast neural network training for library-based critical dimension (CD) metrology

Granted: March 28, 2017
Patent Number: 9607265
Embodiments are generally directed to neural network training for library-based critical dimension metrology. An embodiment of a method includes optimizing a threshold for a principal component analysis of a spectrum data set to provide a principal component value, estimating a training target for one or more neural networks, training the one or more neural networks based both on the training target and on the principal component value provided from optimizing the threshold for the…