公开(公告)号：US10458912B2

公开(公告)日：2019-10-29

申请号：US15649843

申请日：2017-07-14

Applicant: KLA-Tencor Corporation

Inventor： Houssam Chouaib ,  Qiang Zhao ,  Andrei V. Shchegrov ,  Zhengquan Tan

IPC: G01B11/30 ,  G01N21/47 ,  G01N21/95 ,  G01B11/24 ,  G03F7/20 ,  G01N21/21 ,  G01N21/956 ,  G01N21/88

Abstract: Methods and systems for performing optical, model based measurements of a small sized semiconductor structure employing an anisotropic characterization of the optical dispersion properties of one or more materials comprising the structure under measurement are presented herein. This reduces correlations among geometric parameters and results in improved measurement sensitivity, improved measurement accuracy, and enhanced measurement contrast among multiple materials under measurement. In a further aspect, an element of a multidimensional tensor describing the dielectric permittivity of the materials comprising the structure is modelled differently from another element. In a further aspect, model based measurements are performed based on measurement data collected from two or more measurement subsystems combined with an anisotropic characterization of the optical dispersion of the materials under measurement. In another aspect, the characterization of the optical dispersion of one or more materials comprising the structure under measurement depends on the geometry of the structure.

公开(公告)号：US10151986B2

公开(公告)日：2018-12-11

申请号：US14790793

申请日：2015-07-02

Applicant: KLA-Tencor Corporation

Inventor： Andrei V. Shchegrov ,  Thaddeus Gerard Dziura ,  Stilian Ivanov Pandev ,  Leonid Poslavsky

IPC: G03F7/20 ,  H01L21/66

Abstract: Methods and systems for estimating values of parameters of interest of actual device structures based on optical measurements of nearby metrology targets are presented herein. High throughput, inline metrology techniques are employed to measure metrology targets located near actual device structures. Measurement data collected from the metrology targets is provided to a trained signal response metrology (SRM) model. The trained SRM model estimates the value of one or more parameters of interest of the actual device structure based on the measurements of the metrology target. The SRM model is trained to establish a functional relationship between actual device parameters measured by a reference metrology system and corresponding optical measurements of at least one nearby metrology target. In a further aspect, the trained SRM is employed to determine corrections of process parameters to bring measured device parameter values within specification.

公开(公告)号：US10139352B2

公开(公告)日：2018-11-27

申请号：US14882370

申请日：2015-10-13

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Wei Lu ,  Andrei V. Shchegrov ,  Pablo Rovira ,  Jonathan M. Madsen

IPC: G01N21/93 ,  G01N21/956

Abstract: Methods and systems for measuring metrology targets smaller than the illumination spot size employed to perform the measurement are described herein. Collected measurement signals contaminated with information from structures surrounding the target area are reconstructed to eliminate the contamination. In some examples, measurement signals associated one or more small targets and one or more large targets located in close proximity to one another are used to train a signal reconstruction model. The model is subsequently used to reconstruct measurement signals from other small targets. In some other examples, multiple measurements of a small target at different locations within the target are de-convolved to estimate target area intensity. Reconstructed measurement signals are determined by a convolution of the illumination spot profile and the target area intensity. In a further aspect, the reconstructed signals are used to estimate values of parameters of interest associated with the measured structures.

公开(公告)号：US10107765B2

公开(公告)日：2018-10-23

申请号：US15671661

申请日：2017-08-08

Applicant: KLA-Tencor Corporation

Inventor： Noam Sapiens ,  Andrei V. Shchegrov ,  Stilian Ivanov Pandev

IPC: G01N21/93 ,  G01N21/95 ,  G01N21/956 ,  G01N21/47

Abstract: In one embodiment, apparatus and methods for determining a parameter of a target are disclosed. A target having an imaging structure and a scatterometry structure is provided. An image of the imaging structure is obtained with an imaging channel of a metrology tool. A scatterometry signal is also obtained from the scatterometry structure with a scatterometry channel of the metrology tool. At least one parameter, such as overlay error, of the target is determined based on both the image and the scatterometry signal.

公开(公告)号：US20180299259A1

公开(公告)日：2018-10-18

申请号：US15950823

申请日：2018-04-11

Applicant: KLA-Tencor Corporation

Inventor： Andrei V. Shchegrov ,  Antonio Arion Gellineau ,  Sergey Zalubovsky

IPC: G01B11/14 ,  H01L21/66 ,  G01B11/26 ,  G03F7/20 ,  G01N21/47 ,  G01N21/95 ,  G01N21/21 ,  G01B11/06 ,  H05G2/00 ,  H01J37/28

Abstract: Methods and systems for characterizing dimensions and material properties of semiconductor devices by transmission small angle x-ray scatterometry (TSAXS) systems having relatively small tool footprint are described herein. The methods and systems described herein enable Q space resolution adequate for metrology of semiconductor structures with reduced optical path length. In general, the x-ray beam is focused closer to the wafer surface for relatively small targets and closer to the detector for relatively large targets. In some embodiments, a high resolution detector with small point spread function (PSF) is employed to mitigate detector PSF limits on achievable Q resolution. In some embodiments, the detector locates an incident photon with sub-pixel accuracy by determining the centroid of a cloud of electrons stimulated by the photon conversion event. In some embodiments, the detector resolves one or more x-ray photon energies in addition to location of incidence.

公开(公告)号：US20180252514A1

公开(公告)日：2018-09-06

申请号：US15861938

申请日：2018-01-04

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Andrei V. Shchegrov ,  Wei Lu

IPC: G01B11/14 ,  G06F7/48 ,  G06T7/60 ,  G03F7/20

Abstract: Methods and systems for robust overlay error measurement based on a trained measurement model are described herein. The measurement model is trained from raw scatterometry data collected from Design of Experiments (DOE) wafers by a scatterometry based overlay metrology system. Each measurement site includes one or more metrology targets fabricated with programmed overlay variations and known process variations. Each measurement site is measured with known metrology system variations. In this manner, the measurement model is trained to separate actual overlay from process variations and metrology system variations which affect the overlay measurement. As a result, an estimate of actual overlay by the trained measurement model is robust to process variations and metrology system variations. The measurement model is trained based on scatterometry data collected from the same metrology system used to perform measurements. Thus, the measurement model is not sensitive to systematic errors, aysmmetries, etc.

公开(公告)号：US20180180406A1

公开(公告)日：2018-06-28

申请号：US15885504

申请日：2018-01-31

Applicant: KLA-Tencor Corporation

Inventor： Noam Sapiens ,  Kevin A. Peterlinz ,  Alexander Buettner ,  Kerstin Purrucker ,  Andrei V. Shchegrov

IPC: G01B11/24 ,  G03F7/20 ,  G01N21/956 ,  G01N21/21

CPC classification number: G01B11/24 ,  G01B2210/56 ,  G01N21/956 ,  G01N2021/213 ,  G03F7/70625

Abstract: Methods and systems are presented to reduce the illumination spot size projected onto a measurement target and associated spillover onto area surrounding a measurement target. In one aspect, a spatial light modulator (SLM) is located in the illumination path between the illumination light source and the measurement sample. The SLM is configured to modulate amplitude, phase, or both, across the path of the illumination light to reduce wavefront errors. In some embodiments, the desired state of the SLM is based on wavefront measurements performed in an optical path of the metrology system. In another aspect, an illumination aperture having an image plane tilted at an oblique angle with respect to a beam of illumination light is employed to overcome defocusing effects in metrology systems that employ oblique illumination of the measurement sample. In some embodiments, the illumination aperture, objective lens, and specimen are aligned to satisfy the Scheimpflug condition.

公开(公告)号：US09784690B2

公开(公告)日：2017-10-10

申请号：US14708058

申请日：2015-05-08

Applicant: KLA-Tencor Corporation

Inventor： Noam Sapiens ,  Andrei V. Shchegrov ,  Stilian Ivanov Pandev

IPC: G01N21/93 ,  G01N21/95 ,  G01N21/956 ,  G01N21/47

CPC classification number: G01N21/93 ,  G01B2210/56 ,  G01N21/4788 ,  G01N21/9501 ,  G01N21/95607 ,  G01N2201/06113 ,  G01N2201/062 ,  G01N2201/10 ,  G01N2201/1296

Abstract: In one embodiment, apparatus and methods for determining a parameter of a target are disclosed. A target having an imaging structure and a scatterometry structure is provided. An image of the imaging structure is obtained with an imaging channel of a metrology tool. A scatterometry signal is also obtained from the scatterometry structure with a scatterometry channel of the metrology tool. At least one parameter, such as overlay error, of the target is determined based on both the image and the scatterometry signal.

公开(公告)号：US20170287751A1

公开(公告)日：2017-10-05

申请号：US15476683

申请日：2017-03-31

Applicant: KLA-Tencor Corporation

Inventor： Alexander Kuznetsov ,  Antonio Arion Gellineau ,  Andrei V. Shchegrov

IPC: H01L21/67 ,  G06F17/50 ,  G06N99/00 ,  G01N21/95

CPC classification number: H01L21/67253 ,  G01B2210/56 ,  G01N21/9501 ,  G01N2201/12 ,  G03F7/705 ,  G03F7/70625 ,  G03F7/70633 ,  G06F17/5009 ,  G06N20/00

Abstract: Methods and systems for measuring process induced errors in a multiple patterning semiconductor fabrication process based on measurements of a specimen and process information from one or more previous process steps employed to fabricate the specimen are presented herein. A metrology tool is employed after a number of process steps have been executed. The metrology tool measures structural parameters of interest of metrology targets on the wafer based on measured signals and process information, and communicates correctable process parameter values to one or more process tools involved in the previous process steps. When executed by the appropriate process tool, the correctable process parameter values reduce process induced errors in the geometry of the structures fabricated by the process flow. In another aspect, multiple metrology tools are used to control a fabrication process in combination with process information from one or more process steps in the process flow.

公开(公告)号：US09778213B2

公开(公告)日：2017-10-03

申请号：US14461416

申请日：2014-08-17

Applicant: KLA-Tencor Corporation

Inventor： Michael S. Bakeman ,  Andrei V. Shchegrov ,  Kevin Peterlinz ,  Thaddeus Gerard Dziura

IPC: G06F17/50 ,  G01N23/223 ,  G01N23/201

CPC classification number: G01N23/223 ,  G01N23/201 ,  G01N2223/6116

Abstract: Methods and systems for performing simultaneous X-ray Fluorescence (XRF) and small angle x-ray scattering (SAXS) measurements over a desired inspection area of a specimen are presented. SAXS measurements combined with XRF measurements enables a high throughput metrology tool with increased measurement capabilities. The high energy nature of x-ray radiation penetrates optically opaque thin films, buried structures, high aspect ratio structures, and devices including many thin film layers. SAXS measurements of a particular location of a planar specimen are performed at a number of different out of plane orientations. This increases measurement sensitivity, reduces correlations among parameters, and improves measurement accuracy. In addition, specimen parameter values are resolved with greater accuracy by fitting data sets derived from both SAXS and XRF measurements based on models that share at least one material parameter. The fitting can be performed sequentially or in parallel.