Hybrid inspectors
Granted: March 13, 2018
Patent Number:
9916965
Hybrid inspectors are provided. One system includes computer subsystem(s) configured for receiving optical based output and electron beam based output generated for a specimen. The computer subsystem(s) include one or more virtual systems configured for performing one or more functions using at least some of the optical based output and the electron beam based output generated for the specimen. The system also includes one or more components executed by the computer subsystem(s), which…
Optical die to database inspection
Granted: March 13, 2018
Patent Number:
9915625
Methods and systems for detecting defects on a wafer are provided. One system includes one or more computer subsystems configured for generating a rendered image based on information for a design printed on the wafer. The rendered image is a simulation of an image generated by an optical inspection subsystem for the design printed on the wafer. Generating the rendered image includes one or more steps, and the computer subsystem(s) are configured for performing at least one of the one or…
Wafer inspection
Granted: March 13, 2018
Patent Number:
9915622
Systems configured to inspect a wafer are provided. One system includes an illumination subsystem configured to direct pulses of light to an area on a wafer; a scanning subsystem configured to scan the pulses of light across the wafer; a collection subsystem configured to image pulses of light scattered from the area on the wafer to a sensor, wherein the sensor is configured to integrate a number of the pulses of scattered light that is fewer than a number of the pulses of scattered…
Optical metrology with small illumination spot size
Granted: March 13, 2018
Patent Number:
9915524
Methods and systems are presented to reduce the illumination spot size projected onto a measurement target and associated spillover onto area surrounding a measurement target. In one aspect, a spatial light modulator (SLM) is located in the illumination path between the illumination light source and the measurement sample. The SLM is configured to modulate amplitude, phase, or both, across the path of the illumination light to reduce wavefront errors. In some embodiments, the desired…
Optimized spatial modeling for optical CD metrology
Granted: March 13, 2018
Patent Number:
9915522
Provided are scatterometry techniques for evaluating a 3D diffracting structure. In one embodiment, a method involves providing a 3D spatial model of the diffracting structure and discretizing the model into a 3D spatial mesh. The method includes approximating 3D fields for each element of the 3D mesh using 3D spatial basis functions and generating a matrix including coefficients of the 3D spatial basis functions approximating the fields. The coefficients of the 3D spatial basis…
Metrology target identification, design and verification
Granted: March 6, 2018
Patent Number:
9910953
A metrology design and verification framework is provided, which includes methods and systems for metrology structure identification in an integrated circuit design data block, design rule checking, hierarchal design of metrology target structures to minimize random errors, and metrology design rule verification of metrology target design files. In-die metrology targets are identified using various filtering methods and/or designed as hierarchical structure within dies or outside the…
Pupil plane calibration for scatterometry overlay measurement
Granted: March 6, 2018
Patent Number:
9909982
Methods and calibrations modules are provided, for calibrating a pupil center in scatterometry overlay measurements. The calibration comprises calculating fluctuations from a first statistical figure of merit such as an average of an overlay signal per pixel at the pupil and significantly reducing, for example minimizing, the fluctuations with respect to a second statistical figure of merit thereof, such as a pupil weighted variance of the fluctuations.
Method and apparatus to fold optics in tools for measuring shape and/or thickness of a large and thin substrate
Granted: February 27, 2018
Patent Number:
9903708
A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.
System and method for imaging a sample with an electron beam with a filtered energy spread
Granted: February 27, 2018
Patent Number:
9905391
A selectively configurable system for directing an electron beam with a limited energy spread to a sample includes an electron source to generate an electron beam having an energy spread including one or more energies, an aperture having an on-axis opening and an off-axis opening, a first assembly of one or more electron lenses with selectively configurable focal powers positioned to collect the beam from the source and direct the beam to the aperture, a second assembly of one or more…
Overlay measurement of pitch walk in multiply patterned targets
Granted: February 27, 2018
Patent Number:
9903813
Multiply patterned metrology targets and target design methods are provided to enable pitch walk measurements using overlay measurements. Multiply patterned structures having single features or spacers produced simultaneously and sharing a common pitch with the paired features or spacers are used to express pitch walk as a measurable overlay between the structures. For example, targets are provided which comprise a first multiply patterned structure having a single left-hand feature or…
System and method for inhibiting VUV radiative emission of a laser-sustained plasma source
Granted: February 20, 2018
Patent Number:
9899205
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 configured to focus the pump illumination from the pumping source into the volume of the gas mixture in order to generate a plasma within the volume of the gas mixture that emits broadband radiation. The gas containment element may be configured to contain a volume of a gas mixture including a first gas component and a…
Method and system for defect classification
Granted: February 20, 2018
Patent Number:
9898811
Defect classification includes acquiring one or more images of a specimen, receiving a manual classification of one or more training defects based on one or more attributes of the one or more training defects, generating an ensemble learning classifier based on the received manual classification and the attributes of the one or more training defects, generating a confidence threshold for each defect type of the one or more training defects based on a received classification purity…
System and method for drift compensation on an electron beam based characterization tool
Granted: February 13, 2018
Patent Number:
9892885
A scanning electron microscopy system includes an electron beam source, a sample stage that includes a first alignment feature, an electron-optical column that includes electron-optical elements that include a lens having a second alignment feature, and an alignment plate having a third alignment feature. The system additionally includes a reference target, and a detector assembly. The electron-optical elements configurable to simultaneously focus on a substrate and the reference target.…
Monitoring changes in photomask defectivity
Granted: February 13, 2018
Patent Number:
9892503
A reticle that is within specifications is inspected to generate baseline candidate defects and their location and size. After using the reticle in photolithography, the reticle is inspected to generate current candidate defects and their location and size. An inspection report of filtered candidate defects and their images is generated so that these candidate defects include a first subset of the current candidate defects and their images and exclude a second subset of the current…
Adaptive sampling for process window determination
Granted: February 13, 2018
Patent Number:
9891538
Methods and systems for determining a process window for a process performed on a specimen are provided. In general, the embodiments preferentially sample locations in an instance of at least a portion of a device formed on a specimen at a value of a parameter of a process performed on the specimen that is closest to an edge of a determined process window for the process. If defects are detected at the sampled locations, then the sampling may be performed again but for a different…
Spectral purity filters (SPF), support structures for SPF films and corresponding methods of manufacture
Granted: February 13, 2018
Patent Number:
9891356
A device includes spectral purity filters (SPF) and structures for supporting SPF films. The device further includes a monolithic support having a mesh portion and a frame portion and a film overlaying at least a portion of the support. In some cases, the film can be affixed to the support without an adhesive. The monolithic support can be Silicon, stainless steel or some other suitable material and the film can be a single layer spectral purity filter film or a multilayer spectral…
TDI sensor in a darkfield system
Granted: February 13, 2018
Patent Number:
9891177
A wafer scanning system includes imaging collection optics to reduce the effective spot size. Smaller spot size decreases the number of photons scattered by the surface proportionally to the area of the spot. Air scatter is also reduced. TDI is used to produce a wafer image based on a plurality of image signals integrated over the direction of linear motion of the wafer. An illumination system floods the wafer with light, and the task of creating the spot is allocated to the imaging…
System and method for oblique incidence scanning with 2D array of spots
Granted: February 13, 2018
Patent Number:
9891175
A system to generate multiple beam lines in an oblique angle multi-beam spot scanning wafer inspection system includes a beam scanning device configured to scan a beam of illumination, an objective lens oriented at an oblique angle relative to the surface of a sample and with an optical axis perpendicular to a first scanning direction on the sample, and one or more optical elements positioned between the objective lens and the beam scanning device. The one or more optical elements split…
Line scan knife edge height sensor for semiconductor inspection and metrology
Granted: February 6, 2018
Patent Number:
9885656
This semiconductor inspection and metrology system includes a knife-edge mirror configured to receive light reflected from a wafer. The knife-edge mirror is positioned at a focal point of the light reflected from the wafer such that the reflective film on the knife-edge mirror is configured to block at least some of the light reflected from the wafer. The portion of blocked light changes when the light reflected from the wafer is under-focused or over-focused. At least one sensor…
Miniaturized imaging apparatus for wafer edge
Granted: February 6, 2018
Patent Number:
9885671
Disclosed are methods and apparatus for imaging a rounded edge of a sample, such as a wafer with a beveled edge. In one embodiment, the system includes a curved diffuser having an internal surface for positioning towards the rounded edge of the sample and an external surface opposite the internal surface and light sources for generating a plurality of illumination beams adjacent to a plurality of positions on the external surface of the diffuser so that the diffuser outputs uniform light…
