Skip to content

JASCO JASCO

  • News
  • Events
  • E-Store
  • My Account
  • Contact Us
  • Worldwide
Search
Click to view menu
MENUMENU
  • Products
    • Chromatography
      • HPLC
      • RHPLC
      • UHPLC
      • LC-MS
      • Preparative LC
      • Analytical SFC
      • Semi-Preparative SFC
      • Hybrid SFC
      • Fuel Analysis by SFC-FID
      • Preparative SFC
      • Supercritical Fluid Extraction
      • Chromatography Software
    • Molecular Spectroscopy
      • Circular Dichroism
      • High-Throughput CD
      • Vibrational CD
      • Circularly Polarized Luminescence (CPL)
      • Polarimeters
      • FTIR Spectrometers
      • FTIR Microscopy
      • FTIR Portable
      • Raman Microscopy
      • Palmtop Raman Spectrometer
      • Probe Raman
      • UV-Visible/NIR Spectrophotometers
      • UV-Visible/NIR Microscopy
      • Fluorescence Spectrophotometers
      • Film Thickness
      • Spectra Manager™ Suite
    • Refurbished
      • Refurbished HPLC Systems
      • HPLC Switching Valves
      • FTIR Accessories
  • Service
    • Service and Support Plans
    • Service Request Form
  • Applications
  • KnowledgeBase
  • Learning Center
    • Best Practice
      • Circular Dichroism Tips & Tricks for Biological Samples
      • CD Scale Calibration with ACS
      • Fluorescence Tips & Tricks
      • Raman Spectroscopy Tips & Tricks
    • Training Videos
      • ChromNAV
      • SF-NAV
      • Circular Dichroism
      • UV-Visible/NIR
      • Fluorescence
    • Training Seminars
      • Training Registration Form
    • Webinars
    • eBooks
    • Theory
      • Theory of Molecular Spectroscopy
      • Chromatography
  • About Us
    • President’s Message
    • Contact
    • History
    • Careers
  • News
  • Events
  • Worldwide
  • Shop
  • My Account
  • Contact Us

Home / Applications / Variable-Angle FTIR Transmittance Measurement with Polarization

  • Industry

  • Technique

Variable-Angle FTIR Transmittance Measurement with Polarization

By Carlos Morillo

PDF IconDownload This Application

April 25, 2024

Introduction

VAT-500i
Figure 1. VAT-500i

In the semiconductor industry, infrared spectroscopy is widely used for routine analysis such as in the quantitation of impurities like oxygen and carbon, characterization of insulator films and thickness measurement of epitaxial films. There are a number of analytical methods that can be used , with transmission measurement being the most popular. However since silicon wafers have high reflectance, the light used for measurement can be reflected back to interferometer, resulting in noise in the infrared spectrum. The VAT-500i Variable-angle transmittance measurement attachment can be used for challenging samples with strong reflectance. Changes in the incident angle blocks the reflection of the light into the interferometer. Also, the noise due to water vapor can be drastically reduced with small changes in the incident angle from 10 to 20 degrees.

Transmission spectrum of SiO2 film under 0 degree incident angle condition
Figure 2 Transmission spectrum of SiO2 film under 0 degree incident angle condition
Transmission spectrum of SiO2 film under several different incident angle conditions from 0 to 20 degree
Figure 3 Transmission spectrum of SiO2 film under several different incident angle conditions from 0 to 20 degree

For applications such as analysis of polymers, film coatings, and dichroic measurement of oriented membranes, a polarizer can be mounted in the optical path of the VAT-500i. Fig. 4 shows the dichroic measurement of an oriented polypropylene film. Using the rotatable sample holder, the orientation of a sample with unknown orientation can be confirmed. In this application note measurements with different angles from 0 and 90 degree confirmed that the main axis of this sample was oriented in 0 degree direction. Fig. 4 shows the absorbance spectra at 0 and 90 degree positions, indicating that this polypropylene is isotactic. In addition, the large difference in absorption at 1168cm-1 and 998 cm-1 is due to crystallization and isotactic helical structure, which can be utilized to determine the degree of crystallization.

Transmission spectrum of dichroism measurement of oriented polypropylene film
Figure 4 Transmission spectrum of dichroism measurement of oriented polypropylene film

Keywords

260-TR-0153, isotactic material, polypropylene, variable angle transmission IR, FTIR, polarization, epitaxial layer, film coating, dichroic,

This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.

Featured Products:

  • Compact fixed range mid-IR spectrometer with options to extend to the NIR/FIR

    FT/IR-4X

  • The IRT-7000 16-element linear array microscope for fast imaging and kinetics.

    IRT-7000 FTIR Microscope

About the Author

Dr. Carlos Morillo received his Post Doc at Advanced Industrial Science & Technology in Fukuoka and was a Research Scientist at Kyushu University in Japan where he lived for several years. Carlos received his Doctor of Engineering from Kyushu University and his Masters and BS from Simon Bolivar University in Caracas Venezuela. He is an Applications Scientist at JASCO.

JASCO Application Note

Variable-Angle FTIR Transmittance Measurement with Polarization

Introduction

VAT-500i
Figure 1. VAT-500i

In the semiconductor industry, infrared spectroscopy is widely used for routine analysis such as in the quantitation of impurities like oxygen and carbon, characterization of insulator films and thickness measurement of epitaxial films. There are a number of analytical methods that can be used , with transmission measurement being the most popular. However since silicon wafers have high reflectance, the light used for measurement can be reflected back to interferometer, resulting in noise in the infrared spectrum. The VAT-500i Variable-angle transmittance measurement attachment can be used for challenging samples with strong reflectance. Changes in the incident angle blocks the reflection of the light into the interferometer. Also, the noise due to water vapor can be drastically reduced with small changes in the incident angle from 10 to 20 degrees.

Transmission spectrum of SiO2 film under 0 degree incident angle condition
Figure 2 Transmission spectrum of SiO2 film under 0 degree incident angle condition
Transmission spectrum of SiO2 film under several different incident angle conditions from 0 to 20 degree
Figure 3 Transmission spectrum of SiO2 film under several different incident angle conditions from 0 to 20 degree

For applications such as analysis of polymers, film coatings, and dichroic measurement of oriented membranes, a polarizer can be mounted in the optical path of the VAT-500i. Fig. 4 shows the dichroic measurement of an oriented polypropylene film. Using the rotatable sample holder, the orientation of a sample with unknown orientation can be confirmed. In this application note measurements with different angles from 0 and 90 degree confirmed that the main axis of this sample was oriented in 0 degree direction. Fig. 4 shows the absorbance spectra at 0 and 90 degree positions, indicating that this polypropylene is isotactic. In addition, the large difference in absorption at 1168cm-1 and 998 cm-1 is due to crystallization and isotactic helical structure, which can be utilized to determine the degree of crystallization.

Transmission spectrum of dichroism measurement of oriented polypropylene film
Figure 4 Transmission spectrum of dichroism measurement of oriented polypropylene film

Keywords

260-TR-0153, isotactic material, polypropylene, variable angle transmission IR, FTIR, polarization, epitaxial layer, film coating, dichroic,

This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.
28600 Mary’s Court, Easton, MD 21601 USA • (800) 333-5272 • Fax: (410) 822-7526 • jascoinc.com/applications

Close

Designed in Tokyo. TRUSTED globally.

View our support plans

Connect with JASCO

  • Facebook
  • Twitter
  • LinkedIn
  • JASCO Sales
  • 800-333-5272

Receive the latest promotions and special offers

  • This field is for validation purposes and should be left unchanged.
  • Careers
  • Press Kit
  • JASCO Privacy Policy
  • Sitemap
  • Environmental Policy

© , JASCO. All Rights Reserved.