KLA-Tencor Patent Grants

Symmetric target design in scatterometry overlay metrology

Granted: August 22, 2017
Patent Number: 9739702
Metrology methods, systems and targets are provided, which implement a side by side paradigm. Adjacent cells with periodic structures are used to extract the overlay error, e.g., by introducing controllable phase shifts or image shifts which enable algorithmic computation of the overlay. The periodic structures are designed to exhibit a rotational symmetry to support the computation and reduce errors.

Measurement systems having linked field and pupil signal detection

Granted: August 22, 2017
Patent Number: 9739719
Methods and systems for simultaneous detection and linked processing of field signals and pupil signals are presented herein. In one aspect, estimates of one or more structural or process parameter values are based on field measurement signals, pupil measurement signals, or both. In addition, the quality of the measurements of the one or more structural or process parameter values is characterized based on the field measurement signals, pupil measurement signals, or both. In some…

Method, computer system and apparatus for recipe generation for automated inspection of semiconductor devices

Granted: August 22, 2017
Patent Number: 9739720
A method, a computer system and an apparatus are disclosed for inspection recipe generation for the automated inspection of semiconductor devices. In order to generate the inspection recipe a reference data set is used. Automatic inspection is carried out with an initial recipe on images of dies of the reference data set (reference wafermap). The detected inspection results from the automatic inspection are classified and the classified inspection results are compared with an expert…

Scatterometry overlay metrology targets and methods

Granted: August 22, 2017
Patent Number: 9740108
Scatterometry overlay (SCOL) targets as well as design, production and measurement methods thereof are provided. The SCOL targets have several periodic structures at different measurement directions which share some of their structural target elements or parts thereof. An array of common elements may have symmetry directions which are parallel to the measurement directions and thus enable compacting the targets or alternatively increasing the area use efficiency of the targets. Various…

Model for accurate photoresist profile prediction

Granted: August 15, 2017
Patent Number: 9733576
A photoresist modelling system includes a mathematical model for a photolithography process. The mathematical model may be executable using a computer processor. The mathematical model may be used to model a photoresist as formed on a semiconductor wafer surface. A blocked polymer concentration gradient equation may be implemented into the mathematical model. The blocked polymer concentration gradient equation may describe an initial concentration gradient of a blocked polymer in the…

Method and apparatus for database-assisted requalification reticle inspection

Granted: August 15, 2017
Patent Number: 9733640
A method embodiment includes providing a reticle design data that specify a plurality of printable features that are formed on the wafer using the reticle and a plurality of nonprintable features that are not formed on the wafer using such reticle, wherein the reticle design data is usable to fabricate the reticle. A reduced design database is generated from the reticle design data and this reduced design database includes a description or map of the nonprintable features of the reticle,…

System and method for enhanced defect detection with a digital matched filter

Granted: August 15, 2017
Patent Number: 9734422
Enhanced defect detection of a sample includes acquiring two or more inspection images from a sample from two or more locations of the sample for a first optical mode. The defect detection also generates an aggregated defect profile based on the two or more inspection images from the two or more locations for the first optical mode for a selected defect type and calculating one or more noise correlation characteristics of the two or more inspection images acquired from the two or more…

Automated inline inspection and metrology using shadow-gram images

Granted: August 15, 2017
Patent Number: 9734568
Shadow-grams are used for edge inspection and metrology of a stacked wafer. The system includes a light source that directs collimated light at an edge of the stacked wafer, a detector opposite the light source, and a controller connected to the detector. The stacked wafer can rotate with respect to the light source. The controller analyzes a shadow-gram image of the edge of the stacked wafer. Measurements of a silhouette of the stacked wafer in the shadow-gram image are compared to…

Method and system for adaptively scanning a sample during electron beam inspection

Granted: August 15, 2017
Patent Number: 9734987
A system for adaptive electron beam scanning may include an inspection sub-system configured to scan an electron beam across the surface of a sample. The inspection sub-system may include an electron beam source, a sample stage, a set of electron-optic elements, a detector assembly and a controller communicatively coupled to one or more portions of the inspection sub-system. The controller may assess one or more characteristics of one or more portions of an area of the sample for…

Sub 200nm laser pumped homonuclear excimer lasers

Granted: August 15, 2017
Patent Number: 9735534
Disclosed are methods and apparatus for generating a sub-200 nm continuous wave (cw) laser. A laser apparatus includes a chamber for receiving at least a rare gas or rare gas mixtures and a pump laser source for generating at least one cw pump laser focused in the chamber for generating at least one laser-sustained plasma in the chamber. The laser apparatus further includes a system for forming an optical cavity in which the at least one laser-sustained plasma serves as an excitation…

System and method for simultaneous dark field and phase contrast inspection

Granted: August 8, 2017
Patent Number: 9726615
An inspection apparatus for simultaneous dark field (DF) and differential interference contrast (DIC) inspection includes an illumination source and a sample stage configured to secure a sample. The inspection apparatus includes a first sensor, a second sensor and an optical sub-system. The optical sub-system includes an objective, one or more optical elements arranged to direct, through the objective, illumination from the one or more illumination sources to a surface of the sample. The…

Apparatus and methods for finding a best aperture and mode to enhance defect detection

Granted: August 8, 2017
Patent Number: 9726617
Disclosed are methods and apparatus for optimizing a mode of an inspection tool. A first image or signal for each of a plurality of first apertures of the inspection tool is obtained, and each first image or signal pertains to a defect area. For each of a plurality of combinations of the first apertures and their first images or signals, a composite image or signal is obtained. Each composite image or signal is analyzed to determine an optimum one of the combinations of the first…

Aperture alignment in scatterometry metrology systems

Granted: August 8, 2017
Patent Number: 9726984
Methods and algorithms are provided, as well as new metrics for misalignment of apertures with respect to the optical axis of a metrology system. The methods comprise aligning aperture(s) to an optical axis of a scatterometry metrology tool using correction term(s) derived by minimizing an overlay variation measure calculated with respect to overlay measurements of a periodic structure. These methods result in highly sensitive misalignment metrics, which may be used in calibration stages…

Defect detection using structural information

Granted: August 8, 2017
Patent Number: 9727047
Systems and methods for detecting defects on a specimen based on structural information are provided. One system includes one or more computer subsystems configured for separating the output generated by a detector of an inspection subsystem in an array area on a specimen into at least first and second segments of the output based on characteristic(s) of structure(s) in the array area such that the output in different segments has been generated in different locations in the array area…

Method and system for measuring heat flux

Granted: August 1, 2017
Patent Number: 9719867
A heat flux sensor equipped measurement wafer includes a substrate, a cover thermally coupled to a portion of the substrate, a sensor cavity formed between the substrate and the cover, a thermal barrier disposed within at least a portion of the sensor cavity, a bottom temperature sensor thermally coupled to the substrate and insulated from the cover by a portion of the thermal barrier and a top temperature sensor thermally coupled to the cover and insulated from the substrate by an…

Scatterometry system and method for generating non-overlapping and non-truncated diffraction images

Granted: August 1, 2017
Patent Number: 9719920
Scatterometry measurement systems, illumination configurations and respective methods are provided, which comprise illumination beams that have vertical projections on a target plane comprising both a parallel component and a perpendicular component, with respect to a target measurement direction. The illumination beams propagate at an angle to the plane defined by the measurement direction and a normal to the targets surface and generate diffraction images which are off-center at the…

Confined illumination for small spot size metrology

Granted: August 1, 2017
Patent Number: 9719932
Methods and systems are described herein for producing high radiance illumination light for use in semiconductor metrology based on a confined, sustained plasma. One or more plasma confining circuits introduce an electric field, a magnetic field, or a combination thereof to spatially confine a sustained plasma. The confinement of the sustained plasma decreases the size of the induced plasma resulting in increased radiance. In addition, plasma confinement may be utilized to shape the…

Wafer edge inspection with trajectory following edge profile

Granted: August 1, 2017
Patent Number: 9719943
This inspection system has an optical head, a support system, and a controller in electrical communication with the support system. The support system is configured to provide movement to the optical head with three degrees of freedom. The controller is programmed to control movement of the optical head using the support system such that the optical head maintains a constant angle of incidence relative to a wafer surface while imaging a circumferential edge of the wafer. An edge profiler…

Measurement model optimization based on parameter variations across a wafer

Granted: August 1, 2017
Patent Number: 9721055
An optimized measurement model is determined based a model of parameter variations across a semiconductor wafer. A global, cross-wafer model characterizes a structural parameter as a function of location on the wafer. A measurement model is optimized by constraining the measurement model with the cross-wafer model of process variations. In some examples, the cross-wafer model is itself a parameterized model. However, the cross-wafer model characterizes the values of a structural…

System and method for transverse pumping of laser-sustained plasma

Granted: August 1, 2017
Patent Number: 9723703
A laser-sustained plasma light source for transverse plasma pumping includes a pump source configured to generate pumping illumination, one or more illumination optical elements and a gas containment structure configured to contain a volume of gas. The one or more illumination optical elements are configured to sustain a plasma within the volume of gas of the gas containment structure by directing pump illumination along a pump path to one or more focal spots within the volume of gas.…