Analysis of silicon wafers by vacuum FTIR

Download PDF August 25, 2022


FTIR-4000 and 6000 Series spectrometers
FTIR-4000 and 6000 Series spectrometers

Due to the high refractive index of silicon wafer samples, there is a correspondingly high reflectance from the sample. If the sample is placed directly in the sample compartment, vertical to the incident source beam, the reflection of the source returns to the interferometer, is reflected by the beamsplitter and then illuminates the sample again. As a result, the sample pathlength of the sample measurement is different from the background measurement and excessive noise is observed due to the atmospheric water vapor, even with a purged instrument. While it is possible to adjust the angle of the sample with respect to the incident source illumination, using an evacuated FTIR instrument allows measurement of the sample vertical to the incident illumination without any interference due to the water vapor.


Resolution:4 cm-1
Fig 1. Measurement of an epi-film on a silicon wafer

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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.