Kla Corporation

Kla Tencor Corporation

Kla-Tencor Technologies Corporation

Jenn-Kuen Leong

Guoheng Zhao

Mehdi Vaez-Iravani

Daniel Ivanov Kavaldjiev

John Fielden

Xuefeng Liu

Yung-Ho Alex Chuang

Anatoly Romanovsky

Zhiwei Xu

Bret Whiteside

Chunhai Wang

An inspection system may include an illumination source to generate an illumination beam, illumination optics to direct the illumination beam to a sample at an off-axis angle along an illumination direction, and collection optics to collect scattered light from the sample in a dark-field mode, where the scattered light from the sample includes surface haze associated with light scattered from a surface of the sample, and where at least a at least a portion of the surface haze has elliptical polarizations. The system may further include pupil-plane optics to convert the polarizations of the surface haze across the pupil to linear polarization that is aligned parallel to a selected haze orientation direction. The system may include a linear polarizer to reject the surface haze aligned parallel to this haze orientation direction and a detector to generate a dark-field image of the sample based on light passed by the linear polarizer.

Continuous degenerate elliptical retarder for sensitive particle detection

A dark-field optical system may include a rotational objective lens assembly with a dark-field objective lens to collect light from a sample within a collection numerical aperture, where the dark-field objective lens includes an entrance aperture and an exit aperture at symmetrically-opposed azimuth angles with respect to an optical axis, a rotational bearing to allow rotation of at least a part of the dark-field objective lens including the entrance aperture and the exit aperture around the optical axis, and a rotational driver to control a rotational angle of the entrance aperture. The system may also include a multi-angle illumination sub-system to illuminate the sample with an illumination beam through the entrance aperture at two or more illumination azimuth angles, where an azimuth angle of the illumination beam on the sample is selectable by rotating the objective lens to any of the two or more illumination azimuth angles.

Apparatus and method for rotating an optical objective

A system may include illumination optics to direct an illumination beam to a sample at an off-axis angle, collection optics to collect scattered light from the sample, and a phase mask located at a first pupil plane to provide different phase shifts for light in two or more pupil regions of a collection area to reshape a point spread function of light scattered from one or more particles on a surface of the sample. The system may further include a polarization rotator located at a second pupil plane, where the polarization rotator provides a spatially-varying polarization rotation angle selected to rotate light scattered from the surface of the sample to a selected polarization angle, a polarizer to reject light polarized along the selected polarization angle, and a detector to generate a dark-field image of the sample based on light passed by the polarizer.

Sensitive particle detection with spatially-varying polarization rotator and polarizer

A dark-field inspection system may include an illumination source to generate an illumination beam, illumination optics configured to direct the illumination beam to a sample at an off-axis angle along an illumination direction, collection optics to collect scattered light from the sample in response to the illumination beam in a dark-field mode, a polarization rotator located at a pupil plane of the one or more collection optics, where the polarization rotator provides a spatially-varying polarization rotation angle selected to rotate light scattered from a surface of the sample to a selected polarization angle, a polarizer aligned to reject light polarized along the selected polarization angle to reject the light scattered from a surface of the sample, and a detector to generate a dark-field image of the sample based on scattered light from the sample passed by the polarizer.

A dark field inspection system may include an illumination source to generate an illumination beam, one or more illumination optics to direct the illumination beam to a sample at an off-axis angle along an illumination direction, a detector, one or more collection optics to generate a dark-field image of the sample on the detector based on light collected from the sample in response to the illumination beam, and a radial polarizer located at a pupil plane of the one or more collection optics, where the radial polarizer rejects light with radial polarization with respect to an apex point in the pupil plane corresponding to specular reflection of the illumination beam from the sample.

Radial polarizer for particle detection

Systems and methods for inspecting a wafer are provided. One system includes an illumination subsystem configured to illuminate the wafer; a collection subsystem configured to collect light scattered from the wafer and to preserve the polarization of the scattered light; an optical element configured to separate the scattered light collected in different segments of the collection numerical aperture of the collection subsystem, where the optical element is positioned at a Fourier plane or a conjugate of the Fourier plane of the collection subsystem; a polarizing element configured to separate the scattered light in one of the different segments into different portions of the scattered light based on polarization; and a detector configured to detect one of the different portions of the scattered light and to generate output responsive to the detected light, which is used to detect defects on the wafer.

Wafer inspection

A surface inspection apparatus and a method are provided which include an illumination system configured to focus a beam of radiation at a non-orthogonal incidence angle to form an illumination line on a surface substantially in a plane of incidence of the focused beam. The apparatus and method further include a collection system configured to image the illumination line onto an array of detectors oriented parallel to the illumination line. The collection system includes an imaging lens for collecting light scattered from the illumination line, a focusing lens for focusing the collected light, and the array of detectors, each configured to detect a corresponding portion of the illumination line. The collection system may be configured to image the illumination line such that the width of the imaged illumination line on the array of detectors is larger than the pixel size of the detectors along the same direction.

Surface inspection system using laser line illumination with two dimensional imaging

A method and system of using exposure control to inspect a surface, such as a wafer. One inspection system comprises charge coupled devices (CCDs) as detectors. The exposure control function of each CCD is used to adjust integration times on individual taps of the CCD such that light scattered from the surface, which may contain multiple scattering regions, is within a dynamic range of the CCD during inspection.

Growing community of inventors

San Jose, CA, United States of America

Jenn-Kuen Leong