Kla Tencor Corporation

Kla Corporation

Kla-tencor Technologies Corporation

Andrei Veldman

John Josef Hench

Andrei V Shchegrov

Thaddeus Gerard Dziura

Antonio Arion Gellineau

Gregory Brady

Daniel C Wack

David Y Wang

Edward R Ratner

Kevin A Peterlinz

Lawrence D Rotter

Derrick A Shaughnessy

Alexander Kuznetsov

Sergey Zalubovsky

Noah Bareket

Houssam Chouaib

Yin Xu

Liequan Lee

Aaron J Rosenberg

Jonathan Iloreta

Abhi Gunde

Kaiwen Xu

Stilian Pandev

Alexander Bykanov

Walter Dean Mieher

Michael S Bakeman

Nikolay Artemiev

Joseph A Di Regolo

Boxue Chen

Yaoming Shi

Methods and systems for characterizing dimensions and material properties of semiconductor devices by full beam x-ray scatterometry are described herein. A full beam x-ray scatterometry measurement involves illuminating a sample with an X-ray beam and detecting the intensities of the resulting zero diffraction order and higher diffraction orders simultaneously for one or more angles of incidence relative to the sample. The simultaneous measurement of the direct beam and the scattered orders enables high throughput measurements with improved accuracy. The full beam x-ray scatterometry system includes one or more photon counting detectors with high dynamic range and thick, highly absorptive crystal substrates that absorb the direct beam with minimal parasitic backscattering. In other aspects, model based measurements are performed based on the zero diffraction order beam, and measurement performance of the full beam x-ray scatterometry system is estimated and controlled based on properties of the measured zero order beam.

Full beam metrology for x-ray scatterometry systems

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 semiconductor metrology tool inspects an area of a semiconductor wafer. The inspected area includes a plurality of instances of a 3D semiconductor structure arranged periodically in at least one dimension. A computer system generates a model of a respective instance of the 3D semiconductor structure based on measurements collected during the inspection. The computer system renders an augmented-reality or virtual-reality (AR/VR) image of the model that shows a 3D shape of the model and provides the AR/VR image to an AR/VR viewing device for display.

Visualization of three-dimensional semiconductor structures

Methods and systems for solving measurement models of complex device structures with reduced computational effort and memory requirements are presented. The computational efficiency of electromagnetic simulation algorithms based on truncated spatial harmonic series is improved for periodic targets that exhibit a fundamental spatial period and one or more approximate periods that are integer fractions of the fundamental spatial period. Spatial harmonics are classified according to each distinct period of the target exhibiting multiple periodicity. A distinct truncation order is selected for each group of spatial harmonics. This approach produces optimal, sparse truncation order sampling patterns, and ensures that only harmonics with significant contributions to the approximation of the target are selected for computation. Metrology systems employing these techniques are configured to measure process parameters and structural and material characteristics associated with different semiconductor fabrication processes.

Optimizing computational efficiency by multiple truncation of spatial harmonics

Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.

Methods and systems for characterization of an x-ray beam with high spatial resolution

A semiconductor metrology tool inspects an area of a semiconductor wafer. The inspected area includes a plurality of instances of a 3D semiconductor structure arranged periodically in at least one dimension. A computer system generates a model of a respective instance of the 3D semiconductor structure based on measurements collected during the inspection. The computer system renders an image of the model that shows a 3D shape of the model and provides the image to a device for display.

Full beam metrology for X-ray scatterometry systems

Methods and systems for evaluating the geometric characteristics of patterned structures are presented. More specifically, geometric structures generated by one or multiple patterning processes are measured by two or more metrology systems in accordance with a hybrid metrology methodology. A measurement result from one metrology system is communicated to at least one other metrology systems to increase the measurement performance of the receiving system. Similarly, a measurement result from the receiving metrology system is communicated back to the sending metrology system to increase the measurement performance of the sending system. In this manner, measurement results obtained from each metrology system are improved based on measurement results received from other cooperating metrology systems. In some examples, metrology capability is expanded to measure parameters of interest that were previously unmeasurable by each metrology system operating independently. In other examples, measurement sensitivity is improved and parameter correlation is reduced.

Hybrid metrology for patterned wafer characterization

The embodiments disclosed herein can enable a target on a semiconductor wafer to be reconstructed and/or imaged. A surface of a target on a semiconductor wafer is measured using a wafer metrology tool. A voxel map of the surface is fixed to match geometry measurements and using scattering density of expected materials. Uniform scaling of the scattering density of all fixed surface voxels can occur.

Phase revealing optical and X-ray semiconductor metrology

Disclosed are apparatus and methods for determining overlay error in a semiconductor target. For illumination x-rays having at least one angle of incidence (AOI), a correlation model is obtained, and the correlation model correlates overlay error of a target with a modulation intensity parameter for each of one or more diffraction orders (or a continuous diffraction intensity distribution) for x-rays scattered from the target in response to the illumination x-rays. A first target is illuminated with illumination x-rays having the at least one AOI and x-rays that are scattered from the first target in response to the illumination x-rays are collected. An overlay error of the first target is determined based on the modulation intensity parameter of the x-rays collected from the first target for each of the one or more diffraction orders (or the continuous diffraction intensity distribution) and the correlation model.

Methods and apparatus for measuring semiconductor device overlay using X-ray metrology

A method for improving computation efficiency for diffraction signals in optical metrology is described. The method includes simulating a set of spatial harmonics orders for a grating structure. The set of spatial harmonics orders is truncated to provide a first truncated set of spatial harmonics orders based on a first pattern. The first truncated set of spatial harmonics orders is modified by an iterative process to provide a second truncated set of spatial harmonics orders based on a second pattern, the second pattern different from the first pattern. Finally, a simulated spectrum is provided based on the second truncated set of spatial harmonics orders.

Computation efficiency by iterative spatial harmonics order truncation

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Sunnyvale, CA, United States of America

Andrei Veldman