公开(公告)号：US11733172B2

公开(公告)日：2023-08-22

申请号：US17313703

申请日：2021-05-06

Applicant: KLA Corporation

Inventor： Anatoly Romanovsky ,  Jenn-Kuen Leong ,  Daniel Kavaldjiev ,  Chunhai Wang ,  Bret Whiteside ,  Zhiwei Xu

IPC: G01N21/88

CPC classification number: G01N21/8806 ,  G01N2021/8822 ,  G01N2201/063

Abstract: 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.

公开(公告)号：US20210010949A1

公开(公告)日：2021-01-14

申请号：US16913396

申请日：2020-06-26

Applicant: KLA Corporation

Inventor： Zhiwei Xu ,  Kurt Haller ,  J.K. Leong ,  Christian Wolters

IPC: G01N21/95 ,  G01N21/45

Abstract: Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.

公开(公告)号：US11703460B2

公开(公告)日：2023-07-18

申请号：US16913396

申请日：2020-06-26

Applicant: KLA Corporation

Inventor： Zhiwei Xu ,  Kurt Haller ,  J. K. Leong ,  Christian Wolters

IPC: G01N21/95 ,  G01N21/45

CPC classification number: G01N21/9505 ,  G01N21/45 ,  G01N2201/064 ,  G01N2201/06113

Abstract: Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.

公开(公告)号：US11181484B1

公开(公告)日：2021-11-23

申请号：US16882603

申请日：2020-05-25

Applicant: KLA CORPORATION

Inventor： Zhiwei Xu ,  Bret Whiteside ,  Steve Yifeng Cui ,  Stephen Biellak

IPC: G01N21/88 ,  G01N21/95 ,  H01L21/67

Abstract: Systems, methods, and apparatuses are disclosed herein for directing, using an optical arrangement including one or more lenses, a main beam and a leading beam toward a specimen such that the main beam is incident on the specimen at a main beam incidence and the leading beam is incident on the specimen at a leading beam incidence. The main beam intensity is greater than a leading beam intensity of the leading beam. A TDI sensor receives electromagnetic radiation from the leading beam incidence, thereby generating a first accumulated charge portion, and receives electromagnetic radiation from the main beam incidence, thereby generating a second accumulated charge portion. A processor maps the first accumulated charge portion to a first FOV, thereby yielding leading beam data, and maps the second accumulated charge portion to a second FOV, thereby yielding main beam data.

公开(公告)号：US20220091047A1

公开(公告)日：2022-03-24

申请号：US17224913

申请日：2021-04-07

Applicant: KLA Corporation

Inventor： Anatoly Romanovsky ,  Zhiwei Xu ,  Yury Yuditsky ,  Yifeng Cui ,  Mandar Paranjape

IPC: G01N21/95 ,  H01L21/66 ,  G01N21/88

Abstract: 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.