KLA-Tencor Patent Grants

System and method for semiconductor wafer inspection and metrology

Granted: May 23, 2017
Patent Number: 9658150
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…

TDI imaging system with variable voltage readout clock signals

Granted: May 23, 2017
Patent Number: 9658170
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…

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

Granted: May 23, 2017
Patent Number: 9659670
Computer-implemented methods, computer-readable media, and systems for classifying defects detected in a memory device area on a wafer are provided.

Low noise, high stability, deep ultra-violet, continuous wave laser

Granted: May 23, 2017
Patent Number: 9660409
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…

Dual wavelength dual interferometer with combiner-splitter

Granted: May 16, 2017
Patent Number: 9651359
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…

Methods and systems for creating or performing a dynamic sampling scheme for a process during which measurements are performed on wafers

Granted: May 16, 2017
Patent Number: 9651943
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…

Machine learning method and apparatus for inspecting reticles

Granted: May 16, 2017
Patent Number: 9652843
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…

Method and system for reducing charging artifacts in scanning electron microscopy images

Granted: May 16, 2017
Patent Number: 9653257
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…

System and method for non-contact wafer chucking

Granted: May 16, 2017
Patent Number: 9653338
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…

Method and system for controlling convection within a plasma cell

Granted: May 16, 2017
Patent Number: 9655225
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…

Structured illumination for contrast enhancement in overlay metrology

Granted: May 9, 2017
Patent Number: 9645079
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…

System and method for apodization in a semiconductor device inspection system

Granted: May 9, 2017
Patent Number: 9645093
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…

In-line wafer edge inspection, wafer pre-alignment, and wafer cleaning

Granted: May 9, 2017
Patent Number: 9645097
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…

Flexible optical aperture mechanisms

Granted: May 9, 2017
Patent Number: 9645287
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.

Detection of selected defects in relatively noisy inspection data

Granted: May 9, 2017
Patent Number: 9646379
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…

Method and apparatus for inspection of light emitting semiconductor devices using photoluminescence imaging

Granted: May 2, 2017
Patent Number: 9638741
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…

Automated inline inspection of wafer edge strain profiles using rapid photoreflectance spectroscopy

Granted: May 2, 2017
Patent Number: 9640449
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.

Hybrid phase unwrapping systems and methods for patterned wafer measurement

Granted: April 25, 2017
Patent Number: 9632038
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…

Lens array-based illumination for wafer inspection

Granted: April 18, 2017
Patent Number: 9625726
Systems configured to provide illumination for wafer inspection performed by a wafer inspection tool are provided. One system includes one or more pupil lenses configured to focus a first far field pattern having a shape different than a shape of light generated by a light source. The system also includes a field lens array positioned between the one or more pupil lenses and an aperture stop. In addition, the system includes a lens group configured to focus a second far field pattern…

Source multiplexing illumination for mask inspection

Granted: April 18, 2017
Patent Number: 9625810
Methods and systems for source multiplexing illumination for mask inspection are disclosed. Such illumination systems enable EUV sources of small brightness to be used for EUV mask defect inspection at nodes below the 22 nm. Utilizing the multiple plane or conic mirrors that are either attached to a continuously rotating base with different angles or individually rotating to position for each pulse, the reflected beams may be directed through a common optical path. The light may then be…