Abstract: A beam splitter includes first and second prisms. The first prism includes first, second, and third optical surfaces. The second prism includes three surfaces, one of which faces the second surface of the first prism and both transmit and reflect light. The first surface of the first prism is curved and forms a lens for focusing light either transmitted or reflected by the common interface between the two prisms. The first prism is from a single piece of material. Fabrication includes making two cuts through a lens to cut-out an intermediate section. A portion of the intermediate section is cut-off to form the third surface of the first prism. The first surface of the first prism corresponds to the curved top surface of the lens. The second surface of the first prism corresponds to the bottom plano surface of the lens. The first and second prisms are then combined.

Abstract: A Time Delay and Integration (TDI) imaging system utilizing variable voltage readout clock signals having progressively increasing amplitudes defined as a function of pixel row location, where pixel rows positioned to receive/collect/transfer image-related charges at the start of the TDI imaging process are controlled using lower amplitude readout clock signals than pixel rows positioned to receive/collect/transfer image-related charges near the end of the TDI process. The clock signal amplitude for each pixel row is determined by the expected maximum amplitude needed to hold and transfer image charges by the pixels of that row. Multiple (e.g., three) primary phase signals are generated that are passed through splitters to provide multiple identical secondary phase signals, and then drivers having gain control circuitry are utilized to produce voltage readout clock signals having the same phases as the primary phase signals, but having two or more different voltage amplitudes.

Abstract: A laser for generating deep ultra-violet (DUV) continuous wave (CW) light includes a second-harmonic generator and a fourth-harmonic generator. The fourth-harmonic generator includes a plurality of mirrors as well as a first non-linear optical (NLO) crystal and a pair of tilted plates. The first NLO crystal generates the light having the fourth harmonic wavelength and a first astigmatism, and is placed in operative relation to the plurality of mirrors. The pair of tilted plates is placed in operative relation to the first NLO crystal such that the light having the second harmonic wavelength passes through both of the tilted plates. Notably, the pair of tilted plates are disposed at substantially equal and opposite angles about respective parallel axes such that they introduce a second astigmatism that corrects for the first astigmatism while minimizing displacement of the circulated light.

Abstract: A system determines a value, such as a thickness, surface roughness, material concentration, and/or critical dimension, of a layer on a wafer based on normalized signals and reflected total intensities. A light source directs a beam at a surface of the wafer. A sensor receives the reflected beam and provides at least a pair of polarization channels. The signals from the polarization channels are received by a controller, which normalizes a difference between a pair of the signals to generate the normalized result. The value of the wafer is determined through analyzing the signal with a modeling of the system.

Abstract: Computer-implemented methods, computer-readable media, and systems for classifying defects detected in a memory device area on a wafer are provided.

Abstract: Various methods and systems for creating or performing a dynamic sampling scheme for a process during which measurements are performed on wafers are provided. One method for creating a dynamic sampling scheme for a process during which measurements are performed on wafers includes performing the measurements on all of the wafers in at least one tot at all measurement spots on the wafers. The method also includes determining an optimal sampling scheme, an enhanced sampling scheme, a reduced sampling scheme, and thresholds for the dynamic sampling scheme for the process based on results of the measurements. The thresholds correspond to values of the measurements at which the optimal sampling scheme, the enhanced sampling scheme, and the reduced sampling scheme are to be used for the process.

Abstract: A plasma cell for controlling convection includes a transmission element configured to receive illumination from an illumination source in order to generate a plasma within a plasma generation region of the volume of gas. The transmission element of the plasma cell is at least partially transparent to at least a portion of the illumination generated by the illumination source and at least a portion of broadband radiation emitted by the plasma. The plasma cell also includes one or more gas return channels formed within the transmission element for transferring gas from a region above the plasma generation region to a region below the plasma generation region.

Abstract: The system includes a dual interferometer sub-system including a first and second channel. The system includes an illumination source. The illumination source includes a first laser source disposed along a first input path and a second laser source disposed along a second input path. The illumination sources includes a combiner-splitter element optically coupled to an output of the first laser source and an output of the second laser source and is configured to combine light of a first wavelength from the first laser source and light of a second wavelength from the second laser source. The combiner-splitter element is further configured to split the combined light into a first channel and a second channel of the dual interferometer sub-system, where the first and second each receive a portion of the light of the first wavelength and the light of the second wavelength.

Abstract: Apparatus and methods for inspecting a specimen are disclosed. An inspection tool is used at one or more operating modes to obtain images of a plurality of training regions of a specimen, and the training regions are identified as defect-free. Three or more basis training images are derived from the images of the training regions. A classifier is formed based on the three or more basis training images. The inspection system is used at the one or more operating modes to obtain images of a plurality of test regions of a specimen. Three or more basis test images are derived from to the test regions. The classifier is applied to the three or more basis test images to find defects in the test regions.

Abstract: A scanning electron microscopy system for mitigating charging artifacts includes a scanning electron microscopy sub-system for acquiring multiple images from a sample. The images include one or more sets of complementary images. The one or more sets of complementary images include a first image acquired along a first scan direction and a second image acquired along a second scan direction opposite to the first scan direction. The system includes a controller communicatively coupled to the scanning electron microscopy sub-system. The controller is configured to receive images of the sample from the scanning electron microscopy sub-system. The controller is further configured to generate a composite image by combining the one or more sets of complementary images.

Abstract: A non-contact wafer chucking apparatus includes a wafer chuck and a gripper assembly coupled to a portion of the wafer chuck. The wafer chuck includes pressurized gas elements configured to generate pressurized gas regions across a surface of the wafer chuck suitable for elevating the wafer above the surface of the wafer chuck. The wafer chuck further includes vacuum elements configured to generate reduced pressure regions across the surface of the wafer chuck having a pressure lower than the pressurized gas regions. The reduced pressure regions are suitable for securing the wafer above the wafer chuck without contact to the wafer chuck. The chucking apparatus includes a rotational drive unit configured to selectively rotate the wafer chuck. The gripper elements are reversibly couplable to an edge portion of the wafer so as to secure the wafer such that the wafer and gripper assembly rotate synchronously with the wafer chuck.

Abstract: An inspection system with selectable apodization includes a selectably configurable apodization device disposed along an optical pathway of an optical system. The apodization device includes one or more apodization elements operatively coupled to one or more actuation stages. The one or more actuation stages are configured to selectably actuate the one or more apodization elements along one or more directions. The inspection system includes a control system communicatively coupled to the one or more actuation stages. The control system is configured to selectably control an actuation state of at the one or more apodization elements so as to apply a selected apodization profile formed with the one or more apodization elements.

Abstract: Contrast enhancement in a metrology tool may include generating a beam of illumination, directing a portion of the generated beam onto a surface of a spatial light modulator (SLM), directing at least a portion of the generated beam incident on the surface of the SLM through an aperture of an aperture stop and onto one or more target structures of one or more samples, and generating a selected illumination pupil function of the illumination transmitted through the aperture utilizing the SLM in order to establish a contrast level of one or more field images of the one or more target structures above a selected contrast threshold, and performing one or more metrology measurements on the one or more target structures utilizing the selected illumination pupil function.

Abstract: A system for providing flexible optical aperture shapes in an optical inspection system (e.g., an optical wafer inspection system) is described. The system includes one or more mechanisms for providing multiple optical aperture shapes along an optical beam path in the optical wafer inspection system. The multiple optical apertures shapes are stacked or overlapped to combine the shapes and form a single combined optical aperture shape along the optical beam path.

Abstract: Methods and systems for detection of selected defects in relatively noisy inspection data are provided. One method includes applying a spatial filter algorithm to inspection data acquired across an area on a substrate to determine a first portion of the inspection data that has a higher probability of being a selected type of defect than a second portion of the inspection data. The selected type of defect includes a non-point defect. The inspection data is generated by combining two or more raw inspection data corresponding to substantially the same locations on the substrate. The method also includes generating a two-dimensional map illustrating the first portion of the inspection data. The method further includes searching the two-dimensional map for an event that has spatial characteristics that approximately match spatial characteristics of the selected type of defect and determining if the event corresponds to a defect having the selected type.

Abstract: Disclosed are methods and apparatus for inspecting and processing semiconductor wafers. The system includes an edge detection system for receiving each wafer that is to undergo a photolithography process. The edge detection system comprises an illumination channel for directing one or more illumination beams towards a side, top, and bottom edge portion that are within a border region of the wafer. The edge detection system also includes a collection module for collecting and sensing output radiation that is scattered or reflected from the edge portion of the wafer and an analyzer module for locating defects in the edge portion and determining whether each wafer is within specification based on the sensed output radiation for such wafer. The photolithography system is configured for receiving from the edge detection system each wafer that has been found to be within specification. The edge detection system is coupled in-line with the photolithography system.

Abstract: Photoreflectance spectroscopy is used to measure strain at or near the edge of a wafer in a production process. The strain measurement is used to anticipate defects and make prospective corrections in later stages of the production process. Strain measurements are used to associate various production steps with defects to enhance later production processes.

Abstract: A method and apparatus for the inspection of light emitting semiconductor devices. The semiconductor device is illuminated with a light source, wherein at least an area of the light emitting semiconductor is illuminated with a waveband of light. The waveband of light ?A+?B can generate electron-hole pairs in the light emitting semiconductor to be inspected. Through an objective lens at least a part of the light ?C emitted by the light emitting semiconductor is detected. The emitted light is captured with a sensor of a camera that is sensitive to wavelengths of the emitted light, wherein the wavelength of the emitted light is above the width of the waveband. The data of the emitted light, captured with the sensor, are transmitted to a computer system for calculating inspection results of the light emitting semiconductor.

Abstract: Disclosed are apparatus and methods for inspecting or measuring a specimen. A system comprises an illumination channel for generating and deflecting a plurality of incident beams to form a plurality of spots that scan across a segmented line comprised of a plurality of scan portions of the specimen. The system also includes one or more detection channels for sensing light emanating from a specimen in response to the incident beams directed towards such specimen and collecting a detected image for each scan portion as each incident beam's spot is scanned over its scan portion. The one or more detection channels include at least one longitudinal side channel for longitudinally collecting a detected image for each scan portion as each incident beam's spot is scanned over its scan portion.

Abstract: 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 map to obtain a back surface map representing the back surface of the wafer; and add the wafer thickness variation map to the back surface phase map to calculate a front surface map representing the front surface of the wafer.