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：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：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.