Kla Tencor Corporation

Kla Corporation

Other

Kla Corporal

David Y Wang

Shankar Krishnan

Lawrence D Rotter

Andrei V Shchegrov

Kevin A Peterlinz

Derrick A Shaughnessy

Johannes D De Veer

Gregory Brady

Guorong Vera Zhuang

Klaus Flock

Andrei Veldman

Muzammil A Arain

Alexander Buettner

Kerstin Purrucker

Xuefeng Liu

Jun Wang

Michael Friedmann

Noam Sapiens

Alexander Kuznetsov

Jonathan M Madsen

Walter H Johnson, Iii

Yang Zhou

Lansheng Dong

Hai-Yang You

Haijing Peng

Catalin Filip

Chunxia Li

Changfei Yan

Rui Ni

Amnon Manassen

Vladimir Levinski

Andrew V Hill

Stilian Pandev

Daniel Kandel

Thaddeus Gerard Dziura

Joel L Seligson

Jianou Shi

Alexander Svizher

Dawei Hu

Barry Blasenheim

Mengmeng Ye

Esen Salcin

Yaolei Zheng

Emanuel Saerchen

Mark Senko

Alex Zheng

The system includes a light source configured to emit light along an illumination path; a projection optical assembly disposed in the illumination path; a target disposed in the illumination path and configured to reflect the light along a collection path; a collection optical assembly disposed in the collection path; a detector disposed in the collection path and configured to detect the light reflected from the target and generate an output signal based on the detected light; and a processor in electronic communication with the detector and configured to generate a measurement of the target based on the output signal. The projection optical assembly defines a first numerical aperture at the target and the collection optical assembly defines a second numerical aperture at the target, and the first numerical aperture is slightly larger than the second numerical aperture for measurements of thick films and high aspect ratio structures.

Measurement of thick films and high aspect ratio structures

Methods and systems for performing spectroscopic ellipsometry measurements of semiconductor structures with reflective collection relay optics having demagnification from the spectrometer slit to the detector are presented herein. The demagnification effectively increases the NA at the detector and reduces the measurement spot size at the wafer imaged onto the detector. In this manner, the demagnification maintains high spectral resolution at the detector, particularly in the ultraviolet wavelength range, e.g., 120-400 nanometers, while maintaining a small collection NA at the wafer, e.g., collection NA less than 0.05. The small collection NA enables high fringe contrast, signal fidelity, and sensitivity, when measuring thick, multiple layer stacks, e.g., 200-300 layers.

Optics for measurement of thick films and high aspect ratio structures

A Cassegrain or quasi-Cassegrain structure objective lens is used in a polar MOKE metrology system. The quasi-Cassegrain reflective objective lens includes a primary concave mirror and a secondary mirror. The primary concave mirror has a wider diameter than the secondary mirror and defines an aperture through which the laser beam is configured to be transmitted toward the secondary mirror. The secondary mirror can be convex, concave, or have a flat surface.

Reflective compact lens for magneto-optic Kerr effect metrology system

Methods and systems for performing measurements of semiconductor structures based on high-brightness, Soft X-Ray (SXR) illumination over a small illumination spot size with a small physical footprint are presented herein. In one aspect, the focusing optics of an SXR based metrology system project an image of the illumination source onto a specimen under measurement with a demagnification of at least 1.25. In a further aspect, an illumination beam path from the x-ray illumination source to the specimen under measurement is less than 2 meters. In another aspect, SXR based measurements are performed with x-ray radiation in the soft x-ray region (i.e., 80-3000 eV). In some embodiments, SXR based measurements are performed at grazing angles of incidence in a range from near zero degrees to 90 degrees. In some embodiments, the illumination optics project an image of an illumination source onto a specimen under measurement with a demagnification of 50, or less.

Methods and systems for compact, small spot size soft x-ray scatterometry

The system includes a modulatable illumination source configured to illuminate a surface of a sample disposed on a sample stage, a detector configured to detect illumination emanating from a surface of the sample, illumination optics configured to direct illumination from the modulatable illumination source to the surface of the sample, collection optics configured to direct illumination from the surface of the sample to the detector, and a modulation control system communicatively coupled to the modulatable illumination source, wherein the modulation control system is configured to modulate a drive current of the modulatable illumination source at a selected modulation frequency suitable for generating illumination having a selected coherence feature length. In addition, the present invention includes the time-sequential interleaving of outputs of multiple light sources to generate periodic pulse trains for use in multi-wavelength time-sequential optical metrology.

Optical metrology tool equipped with modulated illumination sources

A monolithic optical retarder formed from a monolithic prism may include an input face for receiving a light beam, an output face aligned with an optical axis of the light beam prior to entering the input face, and three or more reflection faces. The three or more reflection faces may be oriented to provide an optical path for the light beam from the input face to the output face via reflection by the three or more reflection faces, where the monolithic optical retarder imparts a selected optical retardation on the light beam based on total internal reflection on at least one of the reflection faces. Further, the input face, the output face, and the three or more reflection faces may be oriented such that an optical axis of the light beam exiting the output face is equal to the optical axis of the light beam entering the input face.

Monolithic optical retarder

A metrology system for characterizing a sample formed from a first wafer and a second wafer bonded at an interface with a metrology target near the interface may include a metrology tool and a controller. The metrology tool may include one or more illumination sources and an illumination sub-system to direct illumination from the one or more illumination sources to the metrology target, a detector, and a collection sub-system to collect light from the sample. The light collected from the sample may include light from the metrology target and light from a top surface of the first wafer, and the collection sub-system is may direct the light from the metrology target to the detector. The controller may execute program instructions causing the one or more processors to generate estimates of one or more parameters associated with the sample based on data received from the detector.

Overlay metrology on bonded wafers

A system includes a light source, a Fourier transform infrared reflectometer (FTIR) spectrometer, and broadband reflectometer optics. The system is configured to measure polarized light and unpolarized reflectivities in a wavelength range from 2 &#x3bc;m to 20 &#x3bc;m. The light source can be a laser-driven light source. The spectroscopic reflectometer can include a single channel or two channels.

Multi-environment polarized infrared reflectometer for semiconductor metrology

Methods and systems for performing high throughput spectroscopic measurements of semiconductor structures at mid-infrared wavelengths are presented herein. A Fourier Transform Infrared (FTIR) spectrometer includes one or more measurement channels spanning a wavelength range between 2.5 micrometers and 12 micrometers. The FTIR spectrometer measures a target at multiple different angles of incidence, azimuth angles, different wavelength ranges, different polarization states, or any combination thereof. In some embodiments, illumination light is provided by a laser sustained plasma (LSP) light source to achieve high brightness and small illumination spot size. In some embodiments, FTIR measurements are performed off-axis from the direction normal to the surface of the wafer. In some embodiments, a Stirling cooler extracts heat from the detector of an FTIR spectrometer. In another aspect, measurements performed by one or more spectrometer measurement channels are combined with measurements performed by a mid-infrared FTIR spectrometer channel to characterize high aspect ratio structures.

Mid-infrared spectroscopy for measurement of high aspect ratio structures

Methods and systems for performing spectroscopic measurements of semiconductor structures including ultraviolet, visible, and infrared wavelengths greater than two micrometers are presented herein. A spectroscopic measurement system includes a combined illumination source including a first illumination source that generates ultraviolet, visible, and near infrared wavelengths (wavelengths less than two micrometers) and a second illumination source that generates mid infrared and long infrared wavelengths (wavelengths of two micrometers and greater). Furthermore, the spectroscopic measurement system includes one or more measurement channels spanning the range of illumination wavelengths employed to perform measurements of semiconductor structures. In some embodiments, the one or more measurement channels simultaneously measure the sample throughout the wavelength range. In some other embodiments, the one or more measurement channels sequentially measure the sample throughout the wavelength range.

Methods and systems for measurement of thick films and high aspect ratio structures

A laser beam is directed through a transmissive axicon telescope or a reflective axicon telescope such as in a magneto-optic Kerr effect metrology system. With the transmissive axicon telescope, a Gaussian beam profile is directed through a first axicon lens and a second axicon lens. The first axicon lens and second axicon lens transfer the Gaussian beam profile of the laser beam to a hollowed laser ring. The laser beam with a hollowed laser ring can be directed through a Schwarzschild reflective objective. With the reflective axicon telescope, the laser beam is directed through two conical mirrors that are fully reflective. One of the conical mirrors defines a central hole that the laser beam passes through.

Magneto-optic Kerr effect metrology systems

Methods and systems for performing co-located measurements of semiconductor structures with two or more measurement subsystems are presented herein. To achieve a sufficiently small measurement box size, the metrology system monitors and corrects the alignment of the measurement spot of each metrology subsystem with a metrology target to achieve maximum co-location of the measurement spots of each metrology subsystem with the metrology target. In another aspect, measurements are performed simultaneously by two or more metrology subsystems at high throughput at the same wafer location. Furthermore, the metrology system effectively decouples simultaneously acquired measurement signals associated with each measurement subsystem. This maximizes signal information associated with simultaneous measurements of the same metrology by two or more metrology subsystems.

Methods and systems for co-located metrology

Methods and systems for performing semiconductor measurements based on hyperspectral imaging are presented herein. A hyperspectral imaging system images a wafer over a large field of view with high pixel density over a broad range of wavelengths. Image signals collected from a measurement area are detected at a number of pixels. The detected image signals from each pixel are spectrally analyzed separately. In some embodiments, the illumination and collection optics of a hyperspectral imaging system include fiber optical elements to direct illumination light from the illumination source to the measurement area on the surface of the specimen under measurement and fiber optical elements to image the measurement area. In another aspect, a fiber optics collector includes an image pixel mapper that couples a two dimensional array of collection fiber optical elements into a one dimensional array of pixels at the spectrometer and the hyperspectral detector.

Semiconductor metrology based on hyperspectral imaging

Growing community of inventors

Santa Clara, CA, United States of America

David Y Wang