Kla Tencor Corporation

Kla-tencor Technologies Corporation

Kla Corporation

Christian Wolters

Anatoly Romanovsky

Stephen Biellak

Juergen Reich

Bret Whiteside

Aleksey Petrenko

Guoheng Zhao

David W Shortt

Zhiwei Xu

Daniel Ivanov Kavaldjiev

Kurt Lindsay Haller

Alexander Slobodov

Mehdi Vaez-Iravani

George J Kren

Alexander Belyaev

Paul Doyle

Jijen Vazhaeparambil

Donald Pettibone

Ximan Jiang

Chuanyong Huang

Zhongping Cai

Mous Tatarkhanov

Yung-Ho Alex Chuang

Ian R Smith

Wayne McMillan

Ivan Maleev

Chunsheng J Huang

Yu Guan

Dirk Woll

Raymond Chu

Chunhai Wang

Dieter Wilk

Charles Amsden

Jon Meyer

Howard Dando

J K Leong

Sam Shamouilian

Jiayao Zhang

J Rex Runyon

Richard Fong

Jien Cao

Howard W Dando

Jurgen Reich

Gordana Neskovic

Yevgeny Kruptesky

Don Brayton

Tim Mahatdejkul

Kurt Haller

Steve (Yifeng) Cui

Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.

Methods and systems for optical surface defect material characterization

Methods and systems for reducing illumination intensity while scanning over large particles are presented herein. A surface inspection system determines the presence of a large particle in the inspection path of a primary measurement spot using a separate leading measurement spot. The inspection system reduces the incident illumination power while the large particle is within the primary measurement spot. The primary measurement spot and the leading measurement spot are separately imaged by a common imaging collection objective onto one or more detectors. The imaging based collection design spatially separates the image of the leading measurement spot from the image of the primary measurement spot at one or more wafer image planes. Light detected from the leading measurement spot is analyzed to determine a reduced power time interval when the optical power of the primary illumination beam and the leading illumination beam are reduced.

Surface defect inspection with large particle monitoring and laser power control

An inspection system with radiation-induced false count mitigation includes a radiation count controller coupled to one or more radiation sensors positioned proximate to an illumination sensor oriented to detect illumination from a sample. The radiation count controller may identify a set of radiation detection events based on radiation signals received from the radiation sensors during operation of the illumination sensor. The inspection system may further include an inspection controller to identify a set of illumination detection events based on an illumination signal, identify one or more features on the sample based on the set of illumination detection events, receive the set of radiation detection events from the radiation count controller, compare the set of radiation detection events to the set of illumination detection events to identify a set of coincidence events, and refine the one or more identified features on the sample based on the set of coincidence events.

System and method for reducing radiation-induced false counts in an inspection system

A method and apparatus for producing high frequency dynamically focused oblique laser illumination for a spinning wafer inspection system. The focus is changed by changing the beam direction incidence angle so as to bring focal spot onto the wafer surface. Disclosed herein is a system and method for automatic beam shaping (i.e., spot size) and steering (i.e., position) for a spinning wafer inspection system, combined into a single module. Also disclosed is a method and system for measuring the beam position/size/shape and angle with sufficient resolution to make corrections using feedback from the monitor.

Method and apparatus for producing and measuring dynamically focused, steered, and shaped oblique laser illumination for spinning wafer inspection system

The present disclosure is directed to a method for designing an aperture in a mask for inspecting a wafer. The method includes the steps of scanning a collection plane of the wafer at a plurality of points and collecting data for at least a part of the wafer. The method also includes the step of mapping the data. A further step of the method includes configuring the aperture based on the mapped data.

Haze and defect distribution and aperture configuration in surface metrology inspectors

A wafer scanning system includes imaging collection optics to reduce the effective spot size. Smaller spot size decreases the number of photons scattered by the surface proportionally to the area of the spot. Air scatter is also reduced. TDI is used to produce a wafer image based on a plurality of image signals integrated over the direction of linear motion of the wafer. An illumination system floods the wafer with light, and the task of creating the spot is allocated to the imaging collection optics.

TDI sensor in a darkfield system

An inspection system with radiation-induced false count mitigation includes an illumination source configured to illuminate a sample, a detector assembly comprising an illumination sensor configured to detect illumination from the sample, and one or more radiation sensors configured to detect particle radiation, and control circuitry communicatively coupled to the detector. The control circuitry is configured to perform the steps of determining a set of radiation detection events based on one or more radiation signals received from the radiation sensors, determining a set of imaging events based on the illumination signal received from the illumination sensor, comparing the set of radiation detection events to the set of imaging events to generate a set of coincidence events, wherein the set of coincidence events comprises simultaneous imaging and radiation detection events, and excluding the set of coincidence events from the set of imaging events to generate a set of identified defect sites.

A method and system for providing illumination is disclosed. The method may include providing a laser having a predetermined wavelength; performing at least one of: beam splitting or beam scanning prior to a frequency conversion; converting a frequency of each output beam of the at least one of: beam splitting or beam scanning; and providing the frequency converted output beam for illumination.

Laser with integrated multi line or scanning beam capability

Methods and systems for reshaping the beam intensity distribution of an illumination light supplied to a specimen under inspection are presented. A scanning surface inspection system includes a beam shaping element that flattens the beam intensity distribution of a beam of light generated by an illumination source. The reshaped illumination light is directed to the wafer surface over an illumination spot. With a flattened beam intensity distribution, the incident beam power can be increased without the beam intensity exceeding the damage threshold of the wafer at any particular location. In addition, the illumination spot is shaped by the beam shaping element to have a variable beam width in a direction parallel to the inspection track. The location of a defect within an inspection area having a variable beam width is estimated based on an analysis of the output of the detector.

Inspection beam shaping for improved detection sensitivity

The disclosure is directed to a system and method of managing illumination energy applied to illuminated portions of a scanned wafer to mitigate illumination-induced damage without unnecessarily compromising SNR of an inspection system. The wafer may be rotated at a selected spin frequency for scanning wafer defects utilizing the inspection system. Illumination energy may be varied over at least one scanned region of the wafer as a function of radial distance of an illuminated portion from the center of the wafer and the selected spin frequency of the wafer. Illumination energy may be further applied constantly over one or more scanned regions of the wafer beyond a selected distance from the center of the wafer.

Illumination energy management in surface inspection

The disclosure is directed to a system and method for inspecting a spinning sample by substantially simultaneously scanning multiple spots on a surface of the sample utilizing a plurality of illumination beams. Portions of illumination reflected, scattered, or radiated from respective spots on the surface of the sample are collected by at least one detector array. Information associated with at least one defect of the sample is determined by at least one computing system in communication with the detector array. According to various embodiments, at least one of scan pitch, spot size, spot separation, and spin rate is controlled to compensate pitch error due to tangential spot separation.

Multi-spot defect inspection system

A surface scanning wafer inspection system with independently adjustable scan pitch and associated methods of operation are presented. The scan pitch may be adjusted independently from an illumination area on the surface of a wafer. In some embodiments, scan pitch is adjusted while the illumination area remains constant. For example, defect sensitivity is adjusted by adjusting the rate of translation of a wafer relative to the rate of rotation of the wafer without additional optical adjustments. In some examples, the scan pitch is adjusted to achieve a desired defect sensitivity over an entire wafer. In other examples, the scan pitch is adjusted during wafer inspection to optimize defect sensitivity and throughput. In other examples, the scan pitch is adjusted to maximize defect sensitivity within the damage limit of a wafer under inspection.

Surface scanning inspection system with independently adjustable scan pitch

Method and apparatus for producing and measuring dynamically focussed, steered, and shaped oblique laser illumination for spinning wafer inspection system

Methods, systems, and structures for monitoring incident beam position in a wafer inspection system are provided. One structure includes a feature formed in a chuck configured to support a wafer during inspection by the wafer inspection system. The chuck rotates the wafer in a theta direction and simultaneously translates the wafer in a radial direction during the inspection. An axis through the center of the feature is aligned with a radius of the chuck such that a position of the axis relative to an incident beam of the wafer inspection system indicates changes in the incident beam position in the theta direction.

Monitoring incident beam position in a wafer inspection system

Surface scanning inspection system with adjustable scan pitch

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Campbell, CA, United States of America

Christian Wolters