Methods and apparatus for measuring semiconductor device overlay using X-ray metrology
Granted: February 6, 2018
Patent Number:
9885962
Disclosed are apparatus and methods for determining overlay error in a semiconductor target. For illumination x-rays having at least one angle of incidence (AOI), a correlation model is obtained, and the correlation model correlates overlay error of a target with a modulation intensity parameter for each of one or more diffraction orders (or a continuous diffraction intensity distribution) for x-rays scattered from the target in response to the illumination x-rays. A first target is…
Partly disappearing targets
Granted: February 6, 2018
Patent Number:
9885961
The present disclosure is directed to overlay metrology with targets including “disappearing” or sacrificial layers that leave no optical trace impacting OVL measurement when processed. In an embodiment, an overlay metrology target may include at least one overlay target structure inducing an optical characteristic and at least one secondary overlay target structure inducing a temporary optical characteristic. The at least one secondary overlay target structure being removable by a…
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…
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…
Heat-spreading blanking system for high throughput electron beam apparatus
Granted: January 30, 2018
Patent Number:
9881764
An electron beam apparatus addresses blanking issues resulting from sinking high-power heat onto an aperture diaphragm by evenly spreading heat on the aperture diaphragm. The apparatus can include an aperture diaphragm and a deflector that deflects the electron beam on the aperture diaphragm. The electron beam is directed at the aperture diaphragm in a pattern around the aperture. The pattern may be a circle, square, or polygon. The pattern also may include a variable locus relative to…
Method and apparatus for non-contact measurement of forward voltage, saturation current density, ideality factor and I-V curves in P-N junctions
Granted: January 30, 2018
Patent Number:
9880200
Non-contact measurement of one or more electrical response characteristics of a p-n junction includes illuminating a surface of the p-n junction with light of a first intensity having a modulation or pulsed characteristic sufficient to establish a steady-state condition in a junction photovoltage (JPV) of the p-n junction, measuring a first JPV from the p-n junction within the illumination area, illuminating the surface of the p-n junction with light of an additional intensity, measuring…
Systems and methods for detecting defects on a wafer
Granted: January 30, 2018
Patent Number:
9880107
Systems and methods for detecting defects on a wafer are provided. One method includes generating output for a wafer by scanning the wafer with an inspection system using first and second optical states of the inspection system. The first and second optical states are defined by different values for at least one optical parameter of the inspection system. The method also includes generating first image data for the wafer using the output generated using the first optical state and second…
Apparatus and method for optical metrology with optimized system parameters
Granted: January 30, 2018
Patent Number:
9879977
Methods and systems for achieving a small measurement box size specification across a set of metrology system parameters are presented. The small measurement box size specification is achieved by selectively constraining one or more of the sets of system parameters during measurement. A subset of measurement system parameters such as illumination wavelength, polarization state, polar angle of incidence, and azimuth angle of incidence is selected for measurement to maintain a smaller…
Apparatus and method for shielding a controlled pressure environment
Granted: January 30, 2018
Patent Number:
9879684
An apparatus for shielding a controlled pressure environment, including a shield assembly with: a gate disc arranged for location in a chamber and including a first continuous surface facing an opening in the chamber and including an outer circumference extending past the opening in a radial direction orthogonal to a longitudinal axis passing through the chamber and the opening; and an at least one actuator arranged to displace the gate disc in an axial direction parallel to the…
On-device metrology
Granted: January 23, 2018
Patent Number:
9875946
Methods and systems for performing semiconductor metrology directly on device structures are presented. A measurement model is created based on measured training data collected from at least one device structure. The trained measurement model is used to calculate process parameter values, structure parameter values, or both, directly from measurement data collected from device structures of other wafers. In some examples, measurement data from multiple targets is collected for model…
Sub-pixel and sub-resolution localization of defects on patterned wafers
Granted: January 23, 2018
Patent Number:
9875536
Methods and systems for determining if a defect detected on a specimen is a DOI (Defect of Interest) or a nuisance are provided. One system includes computer subsystem(s) configured for aligning output of an inspection subsystem for an area on a specimen to simulated output of the inspection subsystem for the area on the specimen and detecting a defect in the output for the area on the specimen. The computer subsystem(s) are also configured for determining a location of the defect in the…
Techniques and systems for model-based critical dimension measurements
Granted: January 23, 2018
Patent Number:
9875534
A reticle is inspected with an imaging system to obtain a measured image of a structure on the reticle, and the structure has an unknown critical dimension (CD). Using a model, a calculated image is generated using a design database that describes a pattern used to form the structure on the reticle. The model generates the calculated image based on: optical properties of reticle materials of the structure, a computational model of the imaging system, and an adjustable CD. A norm of a…
Removing process-variation-related inaccuracies from scatterometry measurements
Granted: January 23, 2018
Patent Number:
9874527
Metrology methods and respective software and module are provided, which identify and remove measurement inaccuracy which results from process variation leading to target asymmetries. The methods comprise identifying an inaccuracy contribution of process variation source(s) to a measured scatterometry signal (e.g., overlay) by measuring the signal across a range of measurement parameter(s) (e.g., wavelength, angle) and targets, and extracting a measurement variability over the range…
Methods and apparatus for polarized wafer inspection
Granted: January 23, 2018
Patent Number:
9874526
Disclosed are methods and apparatus for inspecting a semiconductor sample. This system comprises an illumination optics subsystem for generating and directing an incident beam towards a defect on a surface of a wafer. The illumination optics subsystem includes a light source for generating the incident beam and one or more polarization components for adjusting a ratio and/or a phase difference for the incident beam's electric field components. The system further includes a collection…
Method and system for gas flow mitigation of molecular contamination of optics
Granted: January 23, 2018
Patent Number:
9874512
A computer-implemented method for determining an optimized purge gas flow in a semi-conductor inspection metrology or lithography apparatus, comprising receiving a permissible contaminant mole fraction, a contaminant outgassing flow rate associated with a contaminant, a contaminant mass diffusivity, an outgassing surface length, a pressure, a temperature, a channel height, and a molecular weight of a purge gas, calculating a flow factor based on the permissible contaminant mole fraction,…
Reducing algorithmic inaccuracy in scatterometry overlay metrology
Granted: January 16, 2018
Patent Number:
9869543
Methods and systems for minimizing of algorithmic inaccuracy in scatterometry overlay (SCOL) metrology are provided. SCOL targets are designed to limit the number of oscillation frequencies in a functional dependency of a resulting SCOL signal on the offset and to reduce the effect of higher mode oscillation frequencies. The targets are segmented in a way that prevents constructive interference of high modes with significant amplitudes, and thus avoids the inaccuracy introduced by such…
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…
Self-moire target design principles for measuring unresolved device-like pitches
Granted: January 9, 2018
Patent Number:
9864209
Metrology targets and methods are provided, which provide self-Moiré measurements of unresolved target features, i.e., interaction of electromagnetic fields re-scattered off elements within a single target layer provides signals with Moiré pitches that are measurable, although the actual target pitches are unresolved and possibly device-like. Targets comprise cell(s) with interlaced lines of elements having different device-like pitches which are selected to yield resolved Moiré…
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…
