Kla Tencor Corporation

Kla-tencor Technologies Corporation

Kla Corporation

Kla-technor Corporation

Anatoly Romanovsky

Christian Wolters

Bret Whiteside

Stephen Biellak

Daniel Ivanov Kavaldjiev

Alexander Slobodov

Yury Yuditsky

Guoheng Zhao

Ivan Maleev

Dirk Woll

Zhongping Cai

Mehdi Vaez-Iravani

George J Kren

Zhiwei Xu

Donald Pettibone

Ximan Jiang

Aleksey Petrenko

Chunhai Wang

Jijen Vazhaeparambil

Mous Tatarkhanov

Mandar Paranjape

Yung-Ho Alex Chuang

David W Shortt

Juergen Reich

Chunsheng J Huang

Jenn-Kuen Leong

Steve Yifeng Cui

Paul Doyle

Chuanyong Huang

Tyler Trytko

Yifeng Cui

Jingyi Xiong

Richard Fong

Million Daniel

Jien Cao

Steven Biellak

Nadine Asenbaum-Doerre

Steve (Yifeng) Cui

Jeff Chen

A semiconductor wafer is inspected using a main laser beam and a secondary laser beam. The secondary laser beam leads the main laser beam and has lower power than the main laser beam. Using the secondary laser beam, a particle is detected on the semiconductor wafer having a size that satisfies a threshold. In response to detecting the particle, the power of the main laser beam and the power of the secondary laser beam are reduced. The particle passes through the main laser beam with the main laser beam at reduced power. After the particle has passed through the main laser beam with the main laser beam at the reduced power, the power of the main laser beam and the power of the secondary laser beam are restored in a controlled manner that is slower than a single step.

Large-particle monitoring with laser power control for defect inspection

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 laser-beam power-modulation system includes an acousto-optic modulator (AOM) to receive a laser beam and separate the laser beam into a primary beam and a plurality of diffracted beams based on an input signal. The power of the primary beam depends on the input signal. The system also includes a slit to transmit the primary beam and dump the plurality of diffracted beams, a controller to generate a control signal based at least in part on feedback indicative of the power of the primary beam or the power of a beam generated using the primary beam, and a driver to generate the input signal based at least in part on the control signal.

Laser closed power loop with an acousto-optic modulator for power modulation

Systems configured to inspect a wafer are provided. One system includes an illumination subsystem configured to direct pulses of light to an area on a wafer; a scanning subsystem configured to scan the pulses of light across the wafer; a collection subsystem configured to image pulses of light scattered from the area on the wafer to a sensor, wherein the sensor is configured to integrate a number of the pulses of scattered light that is fewer than a number of the pulses of scattered light that can be imaged on the entire area of the sensor, and wherein the sensor is configured to generate output responsive to the integrated pulses of scattered light; and a computer subsystem configured to detect defects on the wafer using the output generated by the sensor.

Wafer inspection

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

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 system for substrate tilt and focus control in an inspection system includes a dynamically actuatable substrate stage assembly including a substrate stage for securing a substrate; a tilt-height detection system including: a height detection sub-system and a tilt detection sub-system. The system further includes a first actuator configured to selectably actuate the substrate along a direction perpendicular to the surface of the substrate at a location of the substrate stage assembly; and an additional actuator configured to selectably actuate the substrate along a direction substantially perpendicular to the surface of the substrate at an additional location of the substrate stage assembly; and a MIMO tilt-focus controller communicatively coupled to the height detection sub-system, the tilt detection sub-system, the first actuator and the additional actuator.

Method and system for simultaneous tilt and height control of a substrate surface in an inspection system

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

A wafer is moved under an inspection spot by a rotary inspection system. The system rotates the wafer about an axis of rotation and translates the wafer along a linear trajectory. When the inspection spot is not aligned with the trajectory of the axis of rotation, an angular error is introduced in the representation of the position of the inspection spot with respect to the wafer by the rotary encoder. The angular error is corrected based on an angular error correction value. The angular error correction value is determined based on the distance between the inspection spot and the trajectory of the axis of rotation, the radial distance between the axis of rotation and the inspection spot at a first instance of a particular angular position, and a second radial distance between the axis of rotation and the inspection location at a second instance of the angular position.

Scanning inspection system with angular correction

Systems configured to inspect a wafer are provided. One system includes an illumination subsystem configured to simultaneously form multiple illumination areas on the wafer with substantially no illumination flux between each of the areas. The system also includes a scanning subsystem configured to scan the multiple illumination areas across the wafer. In addition, the system includes a collection subsystem configured to simultaneously and separately image light scattered from each of the areas onto two or more sensors. Characteristics of the two or more sensors are selected such that the scattered light is not imaged into gaps between the two or more sensors. The two or more sensors generate output responsive to the scattered light. The system further includes a computer subsystem configured to detect defects on the wafer using the output of the two or more sensors.

Various embodiments for extended defect sizing range for wafer inspection are provided. One inspection system includes an illumination subsystem configured to direct light to the wafer. The system also includes an image sensor configured to detect light scattered from wafer defects and to generate output responsive to the scattered light. The image sensor is also configured to not have an anti-blooming feature such that when a pixel in the image sensor reaches full well capacity, excess charge flows from the pixel to one or more neighboring pixels in the image sensor. The system further includes a computer subsystem configured to detect the defects on the wafer using the output and to determine a size of the defects on the wafer using the output generated by a pixel and any neighboring pixels of the pixel to which the excess charge flows.

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Palo Alto, CA, United States of America

Anatoly Romanovsky