Kla Tencor Corporation

Kla Corporation

Kla-tencor Technologies Corporation

Kai Cao

Jamie Michael Sullivan

Wenjian Cai

Richard Wallingford

Xiumei Liu

Mark Shi Wang

Ralph T Johnson

Rex Runyon

Yevgeniy Churin

Henrik Nielsen

Derek Mackay

Meier Yitzhak Brender

Brooke Bruguier

Zhiqin Wang

Matthew Giusti

Paul Donders

Dennis G Emge

Yung-Ho Alex Chuang

David Lee Brown

Ralph C Wolf

Grace H Chen

Bryant Mantiply

Jeongsik Lim

Jamie Sulivan

An auto-focusing system is disclosed. The system includes an illumination source. The system includes an aperture. The system includes a projection mask. The system includes a detector assembly. The system includes a relay system, the relay system being configured to optically couple illumination transmitted through the projection mask to an imaging system. The relay system also being configured to project one or more patterns from the projection mask onto a specimen and transmit an image of the projection mask from the specimen to the detector assembly. The system includes a controller including one or more processors configured to execute a set of program instructions. The program instructions being configured to cause the one or more processors to: receive one or more images of the projection mask from the detector assembly and determine quality of the one or more images of the projection mask.

Automated focusing system for tracking specimen surface with a configurable focus offset

Methods and systems for determining focus settings for use in a specimen scan are provided. One method includes generating a focus map defined as values of best focus as a function of position on a specimen using output generated in one or more pre-focus swaths scanned on the specimen by an output acquisition subsystem configured to direct energy to a specimen, to detect energy from the specimen, and to generate output responsive to the detected energy. The method also includes interpolating the focus map to generate focus settings for a scan performed on the specimen during a process and storing information for the generated focus settings for use in the scan performed on the specimen during the process.

Determining focus settings for specimen scans

A method of scanning a sample includes simultaneously forming a plurality of co-linear scans. Each scan is formed by a sweep of a spot by an acousto-optical device (AOD). The co-linear scans are separated by a predetermined spacing. A first plurality of swaths are formed by repeating the simultaneous forming of the plurality of co-linear scans in a direction perpendicular to the co-linear scans. The first plurality of swaths have an inter-swath spacing that is the same as the predetermined spacing. The predetermined spacing can be a scan length or an integral number of scan lengths. A second plurality of swaths can be formed adjacent to the first plurality of swaths. Forming the second plurality of swaths can be performed in an opposite direction to that of the first plurality of swaths or in a same direction. An inspection system can implement this method by including a diffractive optical element (DOE) path after a magnification changer.

Interleaved acousto-optical device scanning for suppression of optical crosstalk

A bias-variant photomultiplier tube (PMT) includes a photocathode that when operating absorbs photons and emits photoelectrons responsive to the absorbed photons. The bias-variant PMTO also includes a plurality of dynodes that receive the photoelectrons emitted by the photocathode. The plurality of dynodes include a first pair of dynodes having a first bias difference and at least a second pair of dynodes having a second bias difference. The second bias difference is greater than the first bias difference. The bias-variant PMTO also includes an anode to receive photoelectrons directed from the plurality of dynodes.

Bias-variant photomultiplier tube

A spot scanning imaging system with run-time alignment includes a beam scanning device configured to linearly scan a focused beam of illumination across a sample, one or more detectors positioned to receive light from the sample, and a controller communicatively coupled to the beam scanning apparatus, the sample stage, and the one or more detectors. The controller is configured to store a first image, transmit a set of drive signals to at least one of the beam scanning device, the sample stage, or the one or more detectors, compare at least a portion of the second sampling grid to at least a portion of the first sampling grid to determine one or more offset errors, and adjust at least one drive signal in the set of drive signals based on the one or more offset errors such that the second sample grid overlaps the first sample grid.

Systems and methods for run-time alignment of a spot scanning wafer inspection system

A method of scanning a sample includes simultaneously forming a plurality of co-linear scans. Each scan is formed by a sweep of a spot by an acousto-optical device (AOD). The co-linear scans are separated by a predetermined spacing. A first plurality of swaths are formed by repeating the simultaneous forming of the plurality of co-linear scans in a direction perpendicular to the co-linear scans. The first plurality of swaths have an inter-swath spacing that is the same as the predetermined spacing. A second plurality of swaths can be formed adjacent to the first plurality of swaths. Forming the second plurality of swaths can be performed in an opposite direction to that of the first plurality of swaths or in a same direction. An inspection system can implement this method by including a diffractive optical element (DOE) path after a magnification changer.

Disclosed are apparatus and methods for inspecting or measuring a specimen. An incident beam is directed across a plurality of consecutive scan portions of a specimen so that an output beam profile from each scan portion is consecutively collected by a photomultiplier tube (PMT), and the scan portions include at least one or more first scan portions and a next scan portion that is scanned after the one or more first scan portions. After or while the incident beam is directed to the one or more first scan portions of the specimen, an output signal for each first scan portion is obtained based on the output beam profile that is collected by the PMT for each first scan portion. An expected output beam profile for the next scan portion is determined based on the output signal that is obtained for each one or more first scan portions. As the incident beam is directed towards the next scan portion, a gain input to the PMT for the next scan portion is set based on the expected output beam profile so that the gain for such next scan portion results in a measured signal at the PMT that is within a predefined specification of the PMT or other hardware components that receive a measured signal from the PMT.

Enhanced high-speed logarithmic photo-detector for spot scanning system

An inspection system comprises a beam generator module for deflecting spots across scan portions of a specimen. The system also includes detection channels for sensing light emanating from a specimen in response to an incident beam directed towards such specimen and generating a detected image for each scan portion. The system comprises a synchronization system comprising clock generator modules for generating timing signals for deflectors of the beam generator module to scan the spots across the scan portions at a specified frequency and each of the detection channels to generate the corresponding detected image at a specified sampling rate. The timing signals are generated based on a common system clock and cause the deflectors to scan the spots and the detection channels to generate a detected image at a synchronized timing so as to minimize jitter between the scan portions in the response image.

Image synchronization of scanning wafer inspection system

A method and apparatus for propagating charge through a sensor and implementation thereof is provided. The method and apparatus may be used to inspect specimens, the sensor operating to advance an accumulated charge between gates of the TDI sensor. The design implementation provides a set of values representing a plurality of out of phase signals, such as sinusoidal or trapezoidal signals. These out of phase signals are converted and transmitted to the sensor. The converted signals cause the sensor to transfer charges in the sensor toward an end of the sensor. Aspects such as feed through correction and correction of nonlinearities are addressed.

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Fremont, CA, United States of America

Kai Cao