Systems and methods for run-time alignment of a spot scanning wafer inspection system
Granted: January 9, 2018
Patent Number:
9864173
A spot scanning imaging system with run-time alignment includes a beam scanning device configured to linearly scan a focused beam of illumination across a sample, one or more detectors positioned to receive light from the sample, and a controller communicatively coupled to the beam scanning apparatus, the sample stage, and the one or more detectors. The controller is configured to store a first image, transmit a set of drive signals to at least one of the beam scanning device, the sample…
Critical dimension uniformity monitoring for extreme ultraviolet reticles
Granted: January 9, 2018
Patent Number:
9863761
Disclosed are methods and apparatus for facilitating an inspection of a sample using an inspection tool. An inspection tool is used to obtain an image or signal from an EUV reticle that specifies an intensity variation across the EUV reticle, and this intensity variation is converted to a CD variation that removes a flare correction CD variation so as to generate a critical dimension uniformity (CDU) map without the flare correction CD variation. This removed flare correction CD…
Line scan spectroscopic white light interferometry for semiconductor inspection and metrology
Granted: January 9, 2018
Patent Number:
9863756
A device and method for surface height profiling are presented. The device has a source with a source slit through which light is provided. The device includes an objective lens having a reference surface. The objective lens is configured to illuminate a sample with test light from the source and to combine test light reflected from the sample with reference light reflected from the reference surface to form combined light. A spectrometer is positioned to receive the combined light at an…
Sensor with electrically controllable aperture for inspection and metrology systems
Granted: January 2, 2018
Patent Number:
9860466
Pixel aperture size adjustment in a linear sensor is achieved by applying more negative control voltages to central regions of the pixel's resistive control gate, and applying more positive control voltages to the gate's end portions. These control voltages cause the resistive control gate to generate an electric field that drives photoelectrons generated in a selected portion of the pixel's light sensitive region into a charge accumulation region for subsequent measurement, and drives…
Broadband and wide field angle compensator
Granted: January 2, 2018
Patent Number:
9857292
A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are…
Metrology system calibration refinement
Granted: January 2, 2018
Patent Number:
9857291
Methods and systems for matching measurement spectra across one or more optical metrology systems are presented. The values of one or more system parameters used to determine the spectral response of a specimen to a measurement performed by a target metrology system are optimized. The system parameter values are optimized such that differences between measurement spectra generated by a reference system and the target system are minimized for measurements of the same metrology targets.…
Apparatus and methods for reticle handling in an EUV reticle inspection tool
Granted: December 26, 2017
Patent Number:
9851643
Systems and methods to control particle generation in a reticle inspection system are presented. The number of particles added to a reticle during an entire load-inspect-unload sequence of a reticle inspection system is reduced by performing all reticle contact events in a controlled, flowing air environment. In one embodiment, the reticle is fixed to a carrier by clamping outside of the vacuum environment, and the carrier, rather than the reticle, is coupled to the reticle stage of the…
Decreasing inaccuracy due to non-periodic effects on scatterometric signals
Granted: December 26, 2017
Patent Number:
9851300
Methods and metrology modules and tools are provided, which minimize an estimated overlay variation measure at misalignment vector values obtained from a derived functional form of an overlay linear response to non-periodic effects. Provided methods further quantifying target noise due to the non-periodic effects using multiple repeated overlay measurements of the target cells, calculating an ensemble of overlay measurements between the cells over the multiple measurement repeats and…
Small-angle scattering X-ray metrology systems and methods
Granted: December 19, 2017
Patent Number:
9846132
Disclosed are apparatus and methods for performing small angle x-ray scattering metrology. This system includes an x-ray source for generating x-rays and illumination optics for collecting and reflecting or refracting a portion of the generated x-rays towards a particular focus point on a semiconductor sample in the form of a plurality of incident beams at a plurality of different angles of incidence (AOIs). The system further includes a sensor for collecting output x-ray beams that are…
Detecting defects on a wafer using defect-specific and multi-channel information
Granted: December 19, 2017
Patent Number:
9846930
Methods and systems for detecting defects on a wafer using defect-specific and multi-channel information are provided. One method includes acquiring information for a target on a wafer. The target includes a pattern of interest (POI) formed on the wafer and a known defect of interest (DOI) occurring proximate to or in the POI. The method also includes detecting the known DOI in target candidates by identifying potential DOI locations based on images of the target candidates acquired by a…
Method and system for imaging of a photomask through a pellicle
Granted: December 12, 2017
Patent Number:
9842724
A system for imaging a sample through a protective pellicle is disclosed. The system includes an electron beam source configured to generate an electron beam and a sample stage configured to secure a sample and a pellicle, wherein the pellicle is disposed above the sample. The system also includes an electron-optical column including a set of electron-optical elements to direct at least a portion of the electron beam through the pellicle and onto a portion of the sample. In addition, the…
Approach for model calibration used for focus and dose measurement
Granted: December 12, 2017
Patent Number:
9841689
A method is provided that comprises printing FEM wafers having different predefined focus offsets and multiple corresponding sites, measuring signals from the sites, and quantifying a focus inaccuracy by comparing the measured signals from the corresponding sites across the wafers.
Power scalable nonlinear optical wavelength converter
Granted: December 12, 2017
Patent Number:
9841655
A system includes a nonlinear crystal positioned such that a focus of a laser beam is outside the nonlinear crystal in at least one plane perpendicular to a beam propagation direction of the laser beam. The nonlinear crystal is disposed in a crystal mount assembly. A laser beam may be directed at the nonlinear crystal for wavelength conversion. The system may be used as a deep-UV wavelength converter.
System and method for reducing radiation-induced false counts in an inspection system
Granted: December 12, 2017
Patent Number:
9841512
An inspection system with radiation-induced false count mitigation includes an illumination source configured to illuminate a sample, a detector assembly comprising an illumination sensor configured to detect illumination from the sample, and one or more radiation sensors configured to detect particle radiation, and control circuitry communicatively coupled to the detector. The control circuitry is configured to perform the steps of determining a set of radiation detection events based…
Multi-layered target design
Granted: December 12, 2017
Patent Number:
9841370
Multi-layered targets, design files and design and production methods thereof are provided. The multi-layered targets comprise process layers arranged to have parallel segmentation features at specified regions, and target layer comprising target elements which are perpendicular to the parallel segmentation features of the process layers at the specified regions.
Apparatus for shielding a homogenizer
Granted: December 5, 2017
Patent Number:
9835854
A shielding apparatus for protecting a homogenizer in a broadband optical system includes a shielding element and a mounting element configured to secure the shielding element at a position at least proximate to an exit portion of a homogenizer of an optical system, the shielding element being positioned between the exit portion of the homogenizer and an optical outlet of the optical system.
Adaptive nuisance filter
Granted: December 5, 2017
Patent Number:
9835566
Methods and systems for generating inspection results for a specimen with an adaptive nuisance filter are provided. One method includes selecting a portion of events detected during inspection of a specimen having values for at least one feature of the events that are closer to at least one value of at least one parameter of the nuisance filter than the values for at least one feature of another portion of the events. The method also includes acquiring output of an output acquisition…
Periodic patterns and technique to control misalignment between two layers
Granted: December 5, 2017
Patent Number:
9835447
A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.
Alignment of inspection to design using built in targets
Granted: November 28, 2017
Patent Number:
9830421
Methods and systems for determining a position of output generated by an inspection subsystem in design data space are provided. One method includes selecting one or more alignment targets from a design for a specimen. At least a portion of the one or more alignment targets include built in targets included in the design for a purpose other than alignment of inspection results to design data space. At least the portion of the one or more alignment targets does not include one or more…
Method and system for measuring radiation and temperature exposure of wafers along a fabrication process line
Granted: November 21, 2017
Patent Number:
9823121
A measurement wafer device for measuring radiation intensity and temperature includes a wafer assembly including one or more cavities. The measurement wafer device further includes a detector assembly. The detector assembly is disposed within the one or more cavities of the wafer assembly. The detector assembly includes one or more light sensors. The detector assembly is further configured to perform a direct or indirect measurement of the intensity of ultraviolet light incident on a…
