Abstract: The light from an optical metrology device is focused into a measurement spot on a sample using a focusing system. The focusing system uses an image of the light reflected from the measurement spot to determine a best focal position at a desired position of the sample. The focusing system selects a characteristic of reflected light, such as polarization state or wavelengths, to use for focusing. The characteristic of the reflected light that is selected for use in determining focal position is affected different by different portions of the sample. For example, light reflected from a top surface of a sample may have a different characteristic than light reflected by an underlying layer. The selected characteristic of the reflected light is used by the focusing system to focus the measurement spot at the top surface or an underlying layer of the sample.

Abstract: A method for monitoring and controlling a substrate singulation process is described. Device edges are imaged and identified for analysis. Discrepancies in device edges are noted and used to modify a singulation process and to monitor the operation of singulation processes for anomalous behavior.

Abstract: A damper for a semiconductor metrology or inspection system includes a pair of parallel plates with a fluid with a variable viscosity retained between plates. At least one wire is disposed between the plates, which may include one or more sets of lands and grooves. In some implementations, both plates include intermeshed lands and grooves. A controller is configured to provide a current to the at least one wire in order to adjust an electromagnetic field or a current through the fluid. The fluid may be a magnetorheological fluid or an electrorheological fluid in which the viscosity of the fluid is variable based on the electromagnetic field or current through the fluid. The controller varies the current applied to the wire to adjust the viscosity of the fluid to alter the damping of the semiconductor metrology or inspection system based on movement of the stage.

Abstract: An optical device for characterizing a workpiece combines an interferometer with a polarization rotation pellicle, installed in a stand-alone fashion in a spatial gap between the mirrors of the interferometer, and a polarization based phase-shift sensor.

Abstract: A metrology device that can determine at least one characteristics of a sample is disclosed. The metrology device includes an optical system that uses spatially coherent light with a first and a second objective lens as well as a detector that detects light reflected from the sample. The objective lenses use numerical apertures sufficient to produce a small probe size, e.g., less than 200 ?m, while a spatial filter is used to reduce the effective numerical aperture of the optical system as seen by the detector to avoid loss of information and demanding computation requirements caused by the large angular spread due to large numerical apertures. The spatial filter permits light to pass in a desired range of angles, while blocking the remaining light and is positioned to prevent use of the full spatial extent of at least one of the first objective lens and the second objective lens.

Abstract: Defects are detected using data acquired from an interference channel and a polarization modification channel in an interferometer. The interference objective splits a polarized illumination beam into a reference illumination that is reflected by a reference surface without modification to the polarization, and a sample beam that is reflected by a sample surface, that may modify the polarization. Light from the sample beam with no change in polarization is combined with the reference illumination and directed to the interference channel, which may measure the reflectivity and/or topography of the sample. Light from the sample beam with modified polarization is directed to the polarization modification channel. The intensity of the light detected at the polarization modification channel may be used, along with the reflectivity and topography data to identify defects or other characteristics of the sample.

Abstract: Systems and methods for inspecting or characterizing samples, such as by characterizing patterned features or structures of the sample. In an aspect, the technology relates to a method for characterizing a patterned structure of a sample. The method includes directing a pump beam to a first position on a surface of the sample to induce a surface acoustic wave in the sample and directing a probe beam to a second position on the sample, wherein the probe beam is affected by the surface acoustic wave when the probe beam reflects from the surface of the sample. The method also includes detecting the reflected probe beam, analyzing the detected reflected probe beam to identify a frequency mode in the reflected probe beam, and based on the identified frequency mode, determining at least one of a width or a pitch of a patterned feature in the sample.

Abstract: A method for correcting misalignments is provided. An alignment for each device of a group of devices mounted on a substrate is determined. An alignment error for the group of devices mounted on the substrate is determined based on the respective alignment for each device. One or more correction factors are calculated based on the alignment error. The alignment error is corrected based on the one or more correction factors.

Abstract: As feature sizes of semiconductor chips shrink there is a need for tighter overlay between layers in a lithography process. This means more advanced and larger overlay corrections may be necessary to ensure that die are properly manufactured into chips, especially in reconstituted substrates where the die can shift in the process of creating the substrate. Systems and methods for correcting these overlay errors in a lithographic process are provided. Additional rotation (theta) and projected image size (mag) corrections can be made to correct overlay errors present in reconstituted substrates by adjusting the stage and the reticle. Furthermore, these adjustments can be made allowing site-by-site or zone-by-zone corrections instead of a one-time adjustment of the reticle chuck as has been done in the past. These corrections can alleviate some of the issues associated with fan-out wafer-level packaging (FOWLP) and fan-out panel-level packaging (FOPLP).

Abstract: Grating-coupled surface plasmon resonance response of a calibration grating is used to calibrate the azimuth angle offset between a sample on the stage and the plane of incidence (POI) of the optical system of an optical metrology device. The calibration grating is configured to produce grating-coupled surface plasmon resonance in response to the optical characteristics of the optical metrology device. The calibration grating is coupled to the stage and positioned at a known azimuth angle with respect to the optical channel of the optical metrology device while the grating-coupled surface plasmon resonance response of the calibration grating is measured. The azimuth angle between an orientation of the calibration grating and the POI of the optical system is determined based on the grating-coupled surface plasmon resonance response. The determined azimuth angle may then be used to correct for an azimuth angle offset between the sample and the POI.

Abstract: Defects are detected using surface topography data. The defects may be detected by determining topography characteristics within a region of interest on a sample, and the same topography characteristics of at least one reference surface. By comparing the topography characteristics in the region of interest for the sample and reference surface, common pattern structures may be removed, leaving only variations, which may be used to identify the presence of defects. For example, thresholds may be used to identify variations in the topography characteristics as defect candidates. Defects may be identified based on, e.g., size, height, shape, texture, etc. of candidate defects. In some implementations, rather than using a reference surface, the topography characteristic of the surface within the region of interest may be inspected based on prior knowledge of a required surface topography for the region of interest to determine if a defect is present.

Abstract: An optical metrology device, such as an interferometer, detects sub-resolution defects on a sample, i.e., defects that are smaller than a pixel in the detector array of the interferometer. The optical metrology device obtains optical metrology data at each pixel in at least one detector array and determines parameter values of a signal model for a pixel of interest using the optical metrology data received by a plurality of pixels neighboring a pixel of interest. A residual for the pixel of interest is determined using the optical metrology data received by the pixel of interest and determined parameter values for the signal model for the pixel of interest. A defect, which may be smaller than the pixel of interest can then be detected based on the residual for the pixel of interest.

Abstract: An elongated rectangular Rochon polarizer, e.g., having a height to width or depth ratio of at least 2.5, is securely held in a non-adhesive mounting assembly. The mounting assembly includes a plurality of compression elements that press the Rochon polarizer against corresponding reference points to properly align the Rochon polarizer within the mounting assembly. Moreover, air gaps between the Rochon polarizer and the sidewalls of the mounting assembly are provided to minimize thermal conduction between the mounting assembly and the Rochon polarizer and to provide thermal convection to cool the Rochon polarizer, thereby reducing risk of catastrophic delamination of the Rochon polarizer due to thermal effects.

Abstract: An optical metrology device produces beams of light with varying wavelengths in a spectral range for measurement of a sample that is at least partially transparent to the spectral range. The light is obliquely incident on the sample, where a portion of the light is reflected off the top surface and a portion is transmitted through the sample and is reflected off the bottom surface. The incident light and/or reflected light is polarized and a phase modulator, such as a photoelastic modulator or electrooptic modulator, is adjusted based on the wavelengths in each beam of light to produce a same retardation of polarization for each beam of light. The reflected light that is received by a detector does not include light reflected from the bottom surface of the sample. A characteristic of a buried structure below the top surface of the sample is determined using the detected reflected light.

Abstract: An improved stage for the processing of large, thin substrates, such as glass and semiconductor panels. Processing includes lithography, inspection, metrology, grinding, and the like. The stage includes a chuck that moves over a base relative to a device for processing a substrate. The chuck conforms to a geometry of the base while moving relative to the base.

Abstract: Systems and methods for measuring a dimension of a 3D structure of a semiconductor device, such as height of a pad or bump supported by a film layer. The methods can include obtaining raw data implicating a height of the 3D structure with a laser triangulation sensor and adjusting the raw data with a compensation factor that accounts for effects of the film layer and a thickness of the film layer.

Abstract: An interferometer uses a phase shift mask that includes an array of pixels that are aligned with a corresponding array of pixels of a detector. Each pixel in the phase shift mask is adapted to produce one of a number of predetermined phase shifts between a test beam and a reference beam. For example, the pixels may be linear polarizers or phase delay elements having one of the number of polarizer orientations or phase delays to produce the predetermined phase shifts between the test beam and the reference beam. The pixels in the phase shift mask are arranged in the array to include each of the predetermined phase shifts in repeating pixel groups in rows that are one column wide, columns that are one row high, or blocks of multiple rows and columns.

Abstract: A stepper (100) for lithographic processing of semiconductor substrates includes abase (102), a chuck (104) that moves only along an X axis of a coordinate system, a bridge (114) mounted over the base and the chuck, and at least one projection camera (112) mounted on the bridge. The at least one projection camera is movable along a Y axis of the coordinate system. The combined range of travel of the chuck along the X axis and the at least one projection camera along the Y axis is sufficient to address a field of view of the at least one projection camera to substantially an entire substrate (106) mounted on the chuck.

Abstract: A load port for loading wafers to and unloading wafers from a front opening unified pod (FOUP) includes a shield member that covers and provides a seal over an opening of the FOUP. The shield member includes a narrow wafer slot that is sized to allow a single wafer to be loaded to or unloaded from the FOUP but otherwise minimize loss of the purge environment within the FOUP. The shield member is movable so that the wafer slot may be moved vertically to provide a wafer transfer robot access to any desired wafer position within the FOUP. The shield member, for example, may be a flexible sheet that is held taut and is rolled onto and off of at least one roller to vertically position the wafer slot. The shield member may alternatively be one or more rigid members that slide on rails to vertically position the wafer slot.

Abstract: An optical metrology device produces light in a spectral range for measurement of a sample using a tunable Quantum Cascade Laser (QCL). The optical metrology device includes a second channel that is used to diagnose when the tunable QCL is in failure mode, e.g., when it is not producing all wavelengths in the plurality of different wavelength ranges. The second channel includes at least one optical flat that is transmissive to the light produced by the QCL and is separate from the tunable QCL. The optical flat is switchably placed in a beam path of the light produced by the tunable QCL and light transmitted through the optical flat is received by a detector. Using output signals from the detector, a failure mode of the tunable QCL may be determined.