公开(公告)号：US20200284733A1

公开(公告)日：2020-09-10

申请号：US16879531

申请日：2020-05-20

Applicant: KLA Corporation

Inventor： Noam Sapiens ,  Shankar Krishnan ,  David Y. Wang ,  Alexander Buettner ,  Kerstin Purrucker ,  Kevin A. Peterlinz

IPC: G01N21/95 ,  G01B11/06 ,  G01J3/42 ,  G01N21/956 ,  H01L21/66 ,  G01J3/02 ,  G01J3/36 ,  G01J3/10 ,  G01J3/28

Abstract: 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.

公开(公告)号：US20200240907A1

公开(公告)日：2020-07-30

申请号：US16741734

申请日：2020-01-13

Applicant: KLA Corporation

Inventor： David Y. Wang ,  Shankar Krishnan ,  Guorong V. Zhuang

IPC: G01N21/3563 ,  G01N21/47

Abstract: 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.

公开(公告)号：US11906770B2

公开(公告)日：2024-02-20

申请号：US17541037

申请日：2021-12-02

Applicant: KLA Corporation

Inventor： Shankar Krishnan ,  David Y. Wang

IPC: G02B5/30 ,  G02B5/04 ,  G01J3/02 ,  G01J3/14 ,  G02B17/04

CPC classification number: G02B5/3091 ,  G01J3/0224 ,  G01J3/14 ,  G02B5/04 ,  G02B17/04

Abstract: 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.

公开(公告)号：US20230341337A1

公开(公告)日：2023-10-26

申请号：US18185100

申请日：2023-03-16

Applicant: KLA Corporation

Inventor： David Y. Wang ,  Shankar Krishnan

IPC: G01N21/95

CPC classification number: G01N21/9501 ,  G01N2021/9511

Abstract: 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.

公开(公告)号：US20220196576A1

公开(公告)日：2022-06-23

申请号：US17411030

申请日：2021-08-24

Applicant: KLA Corporation

Inventor： David Y. Wang ,  Kerstin Purrucker ,  Michael Friedmann

IPC: G01N23/201

Abstract: 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.

公开(公告)号：US11309202B2

公开(公告)日：2022-04-19

申请号：US17028878

申请日：2020-09-22

Applicant: KLA Corporation

Inventor： Shankar Krishnan ,  David Y. Wang ,  Johannes D. de Veer

IPC: H01L21/68 ,  G01N21/21 ,  G01N21/95 ,  G01B11/06 ,  G01N21/27

Abstract: 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.

公开(公告)号：US11137350B2

公开(公告)日：2021-10-05

申请号：US16741734

申请日：2020-01-13

Applicant: KLA Corporation

Inventor： David Y. Wang ,  Shankar Krishnan ,  Guorong V. Zhuang

IPC: G01N21/35 ,  G01N21/47 ,  G01N21/3563 ,  G01N21/33

Abstract: 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.

公开(公告)号：US20210242060A1

公开(公告)日：2021-08-05

申请号：US17028878

申请日：2020-09-22

Applicant: KLA Corporation

Inventor： Shankar Krishnan ,  David Y. Wang ,  Johannes D. de Veer

IPC: H01L21/68 ,  G01N21/21 ,  G01N21/27 ,  G01N21/95 ,  G01B11/06

Abstract: 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.

公开(公告)号：US20250146893A1

公开(公告)日：2025-05-08

申请号：US18936993

申请日：2024-11-04

Applicant: KLA CORPORATION

Inventor： Houssam Chouaib ,  Zhengquan Tan ,  Shova Subedi ,  Shankar Krishnan ,  David Y. Wang ,  Oleg Shulepov ,  Kevin Peterlinz ,  Natalia Malkova ,  Dawei Hu ,  Carlos Ygartua ,  Isvar Cordova ,  Eric Cheek ,  Roman Sappey ,  Anderson Chou

IPC: G01L1/24 ,  G01B11/06 ,  G01B11/24

Abstract: A workpiece is measured using multiple-pass spectroscopic ellipsometry and multi-wavelength Raman spectroscopy, which may be performed in the same system. These measurements are combined to form combined measured data. A stress measurement of the workpiece is determined using the combined measured data. The stress measurement can be determined using a model or a machine learning algorithm.

公开(公告)号：US20240353321A1

公开(公告)日：2024-10-24

申请号：US18136772

申请日：2023-04-19

Applicant: KLA Corporation

Inventor： David Y. Wang ,  Shankar Krishnan

IPC: G01N21/31 ,  G01N21/21 ,  G01N21/95 ,  G06T7/00 ,  G06V10/143 ,  G06V10/145 ,  G06V10/147 ,  G06V10/70 ,  H04N23/11 ,  H04N25/71

CPC classification number: G01N21/31 ,  G01N21/211 ,  G01N21/9505 ,  G06T7/0004 ,  G06V10/143 ,  G06V10/145 ,  G06V10/147 ,  G06V10/70 ,  H04N23/11 ,  H04N25/71 ,  G06T2207/20081 ,  G06T2207/30148

Abstract: Methods and systems for combined Spectroscopic Reflectometry (SR) and Pattern Recognition (PR) based image measurements of semiconductor structures at high throughput are presented herein. Measurements of large pitch targets and thick targets through die with improved fringe contrast, resolution, and spectral fidelity are enabled. A PR based imaging subsystem generates illumination light ranging from visible to short infrared wavelengths. A SR subsystem generates illumination light ranging from the deep ultraviolet to short infrared wavelengths. The SR subsystem includes low Numerical Aperture (NA) optics to realize a relatively large size illumination and collection spot. Both the SR subsystem and the PR based imaging subsystem share the same objective and resolve signals from different depths of a structure under measurement. In some embodiments, a combined machine learning based measurement model estimates values of one or more parameters of interest based on both SR and PR image signals.