KLA-Tencor Patent Grants

Optical near-field metrology

Granted: November 14, 2023
Patent Number: 11815347
Systems and methods are provided which utilize optical microcavity probes to map wafer topography by near-field interactions therebetween in a manner which complies with high volume metrology requirements. The optical microcavity probes detect features on a wafer by shifts in an interference signal between reference radiation and near-field interactions of radiation in the microcavities and wafer features, such as device features and metrology target features. Various illumination and…

Measurement of overlay error using device inspection system

Granted: October 10, 2023
Patent Number: 11784097
A method and system for measuring overlay in a semiconductor manufacturing process comprise capturing an image of a feature in an article at a predetermined manufacturing stage, deriving a quantity of an image parameter from the image and converting the quantity into an overlay measurement. The conversion is by reference to an image parameter quantity derived from a reference image of a feature at the same predetermined manufacturing stage with known overlay (“OVL”). There is also…

Accelerated training of a machine learning based model for semiconductor applications

Granted: February 14, 2023
Patent Number: 11580375
Methods and systems for accelerated training of a machine learning based model for semiconductor applications are provided. One method for training a machine learning based model includes acquiring information for non-nominal instances of specimen(s) on which a process is performed. The machine learning based model is configured for performing simulation(s) for the specimens. The machine learning based model is trained with only information for nominal instances of additional…

Measuring thin films on grating and bandgap on grating

Granted: January 17, 2023
Patent Number: 11555689
Methods and systems disclosed herein can measure thin film stacks, such as film on grating and bandgap on grating in semiconductors. For example, the thin film stack may be a 1D film stack, a 2D film on grating, or a 3D film on grating. One or more effective medium dispersion models are created for the film stack. Each effective medium dispersion model can substitute for one or more layers. A thickness of one or more layers can be determined using the effective medium dispersion based…

Dynamic amelioration of misregistration measurement

Granted: January 10, 2023
Patent Number: 11551980
A dynamic misregistration measurement amelioration method including taking at least one misregistration measurement at multiple sites on a first semiconductor device wafer, which is selected from a batch of semiconductor device wafers intended to be identical, analyzing each of the misregistration measurements, using data from the analysis of each of the misregistration measurements to determine ameliorated misregistration measurement parameters at each one of the multiple sites,…

Automated accuracy-oriented model optimization system for critical dimension metrology

Granted: December 27, 2022
Patent Number: 11537837
Techniques and systems for critical dimension metrology are disclosed. Critical parameters can be constrained with at least one floating parameter and one or more weight coefficients. A neural network is trained to use a model that includes a Jacobian matrix. During training, at least one of the weight coefficients is adjusted, a regression is performed on reference spectra, and a root-mean-square error between the critical parameters and the reference spectra is determined. The training…

Reduction or elimination of pattern placement error in metrology measurements

Granted: December 27, 2022
Patent Number: 11537043
Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast—in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement…

3D microscope including insertable components to provide multiple imaging and measurement capabilities

Granted: December 27, 2022
Patent Number: 11536940
A three-dimensional (3D) microscope includes various insertable components that facilitate multiple imaging and measurement capabilities. These capabilities include Nomarski imaging, polarized light imaging, quantitative differential interference contrast (q-DIC) imaging, motorized polarized light imaging, phase-shifting interferometry (PSI), and vertical-scanning interferometry (VSI).

Transmission small-angle X-ray scattering metrology system

Granted: December 6, 2022
Patent Number: 11519719
Methods and systems for characterizing dimensions and material properties of semiconductor devices by transmission small angle x-ray scatterometry (TSAXS) systems having relatively small tool footprint are described herein. The methods and systems described herein enable Q space resolution adequate for metrology of semiconductor structures with reduced optical path length. In general, the x-ray beam is focused closer to the wafer surface for relatively small targets and closer to the…

Methods and systems for real time measurement control

Granted: December 6, 2022
Patent Number: 11519869
Methods and systems for improving a measurement recipe describing a sequence of measurements employed to characterize semiconductor structures are described herein. A measurement recipe is repeatedly updated before a queue of measurements defined by the previous measurement recipe is fully executed. In some examples, an improved measurement recipe identifies a minimum set of measurement options that increases wafer throughput while meeting measurement uncertainty requirements. In some…

Nuisance mining for novel defect discovery

Granted: November 29, 2022
Patent Number: 11514357
A method of defect discovery can include providing a nuisance bin in a nuisance filter, partitioning the defect population into a defect population partition, segmenting the defect population partition into a defect population segment, selecting from the defect population segment a selected set of defects, computing one or more statistics of the signal attributes of the defects in the defect population segment, replicating the selected set of defects to yield generated defects, shifting…

Determining critical parameters using a high-dimensional variable selection model

Granted: September 27, 2022
Patent Number: 11456194
A high-dimensional variable selection unit determines a list of critical parameters from sensor data and parametric tool measurements from a semiconductor manufacturing tool, such as a semiconductor inspection tool or other types of semiconductor manufacturing tools. The high-dimensional variable selection model can be, for example, elastic net, forward-stagewise regression, or least angle regression. The list of critical parameters may be used to design a next generation semiconductor…

Bright and clean x-ray source for x-ray based metrology

Granted: April 26, 2022
Patent Number: 11317500
Methods and systems for x-ray based semiconductor metrology utilizing a clean, hard X-ray illumination source are described herein. More specifically, a laser produced plasma light source generates high brightness, hard x-ray illumination having energy in a range of 25,000 to 30,000 electron volts. To achieve high brightness, a highly focused, very short duration laser beam is focused onto a dense Xenon target in a liquid or solid state. The interaction of the focused laser pulse with…

Topographic phase control for overlay measurement

Granted: April 26, 2022
Patent Number: 11314173
Metrology tools and methods are provided, which estimate the effect of topographic phases corresponding to different diffraction orders, which result from light scattering on periodic targets, and adjust the measurement conditions to improve measurement accuracy. In imaging, overlay error magnification may be reduced by choosing appropriate measurement conditions based on analysis of contrast function behavior, changing illumination conditions (reducing spectrum width and illumination…

Process control metrology

Granted: April 26, 2022
Patent Number: 11313809
Methods and systems for estimating values of process parameters based on measurements of structures fabricated on a product wafer are presented herein. Exemplary process parameters include lithography dosage and exposure and lithography scanner aberrations. A measurement model is employed to estimate process parameter values from measurements of structures fabricated on a wafer by a particular fabrication process. The measurement model includes process parameters and geometric parameters…

Systems and methods for optimizing focus for imaging-based overlay metrology

Granted: April 26, 2022
Patent Number: 11313669
Methods and systems for focusing and measuring by mean of an interferometer device, having an optical coherence tomography (OCT) focusing system, by separately directing an overlapped measurement and reference wavefront towards a focus sensor and towards an imaging sensor; where a predefined focusing illumination spectrum of the overlapped wavefront is directed towards the focus sensor, and where a predefined measurement illumination spectrum of the overlapped wavefront is directed…

Method for measuring and correcting misregistration between layers in a semiconductor device, and misregistration targets useful therein

Granted: April 12, 2022
Patent Number: 11302544
A method for measurement of misregistration in the manufacture of semiconductor device wafers, the method including measuring misregistration between layers of a semiconductor device wafer at a first instance and providing a first misregistration indication, measuring misregistration between layers of a semiconductor device wafer at a second instance and providing a second misregistration indication, providing a misregistration measurement difference output in response to a difference…

Space charge insensitive electron gun designs

Granted: April 12, 2022
Patent Number: 11302510
Electron gun systems with a particular inner width dimension, sweep electrodes, or a combination of a particular inner width dimension and sweep electrodes are disclosed. The inner width dimension may be less than twice a value of a Larmor radius of secondary electrons in a channel downstream of a beam limiting aperture, and a Larmor time for the secondary electrons may be greater than 1 ns. The sweep electrode can generates an electric field in a drift region, which can increase kinetic…

3D microscope including insertable components to provide multiple imaging and measurement capabilities

Granted: April 5, 2022
Patent Number: 11294161
A three-dimensional (3D) microscope includes various insertable components that facilitate multiple imaging and measurement capabilities. These capabilities include Nomarski imaging, polarized light imaging, quantitative differential interference contrast (q-DIC) imaging, motorized polarized light imaging, phase-shifting interferometry (PSI), and vertical-scanning interferometry (VSI).

Broad band plasma inspection based on a nuisance map

Granted: April 5, 2022
Patent Number: 11295432
A noise map is used for defect detection. One or more measurements of intensities at one or more pixels are received and an intensity statistic is determined for each measurement. The intensity statistics are grouped into at least one region and stored with at least one alignment target. A wafer can be inspected with a wafer inspection tool using the noise map. The noise map can be used as a segmentation mask to suppress noise.