公开(公告)号：US11243175B2

公开(公告)日：2022-02-08

申请号：US17175179

申请日：2021-02-12

Applicant: KLA Corporation

Inventor： Xuefeng Liu ,  Jenn-Kuen Leong ,  Daniel Kavaldjiev ,  John Fielden

IPC: G01N21/95 ,  H01L21/66 ,  G01N21/21 ,  G01N21/956 ,  G01N21/88

Abstract: A system may include illumination optics to direct an illumination beam to a sample at an off-axis angle, collection optics to collect scattered light from the sample, and a phase mask located at a first pupil plane to provide different phase shifts for light in two or more pupil regions of a collection area to reshape a point spread function of light scattered from one or more particles on a surface of the sample. The system may further include a polarization rotator located at a second pupil plane, where the polarization rotator provides a spatially-varying polarization rotation angle selected to rotate light scattered from the surface of the sample to a selected polarization angle, a polarizer to reject light polarized along the selected polarization angle, and a detector to generate a dark-field image of the sample based on light passed by the polarizer.

公开(公告)号：US11231362B1

公开(公告)日：2022-01-25

申请号：US16723565

申请日：2019-12-20

Applicant: KLA Corporation

Inventor： Guorong V. Zhuang ,  Shankar Krishnan ,  David Y. Wang ,  Xuefeng Liu ,  Mengmeng Ye ,  Dawei Hu

IPC: G01N21/55 ,  G01N21/35 ,  G01N21/21 ,  G01N21/3563

Abstract: 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 μm to 20 μm. The light source can be a laser-driven light source. The spectroscopic reflectometer can include a single channel or two channels.

公开(公告)号：US11899338B2

公开(公告)日：2024-02-13

申请号：US17991198

申请日：2022-11-21

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Kelly Mauser ,  Baigang Zhang ,  Xuefeng Liu ,  John Fielden ,  Yinying Xiao-Li ,  Elena Loginova

IPC: G02F1/35 ,  G02F1/355 ,  G02F1/39 ,  G02F1/37 ,  G01N21/47 ,  G01N21/95 ,  H01S3/16

CPC classification number: G02F1/3534 ,  G01N21/4738 ,  G02F1/3507 ,  G02F1/3542 ,  G02F1/3548 ,  G02F1/3551 ,  G02F1/37 ,  G02F1/392 ,  G01N21/9501 ,  G01N2201/06113 ,  G02F2203/11 ,  H01S3/1625 ,  H01S3/1636

Abstract: A nonlinear crystal including stacked strontium tetraborate SrB4O7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency doubling stage of a laser assembly to generate laser output light having a wavelength in the range of about 180 nm to 200 nm. One or more fundamental laser beams are frequency doubled, down-converted and/or summed using one or more frequency conversion stages to generate an intermediate frequency light with a corresponding wavelength in the range of about 360 nm to 400 nm, and then the final frequency converting stage utilizes the nonlinear crystal to double the frequency of the intermediate frequency light to generate the desired laser output light at high power. Methods, inspection systems, lithography systems and cutting systems incorporating the laser assembly are also described.