Abnormal Behavior of Longitudinal Optical Phonon in Silicon Dioxide Films on 4H-SiC Bulk Epitaxial Substrate Using Fourier Transform Infrared (FT-IR) Spectroscopy

作者：Yoshikawa Masanobu^*; Seki Hirohund; Yamane Tsuneyuki; Nanen Yuichiro; Kato Muneharu; Kimoto Tsunenobu

来源：Applied Spectroscopy, 2013, 67(5): 542-545.

DOI：10.1366/12-06873

• Characterization
• Fourier transform infrared spectroscopy
• FT-IR
• Attenuated total reflection
• ATR
• Surface polariton
• Silicon dioxide films
• 4H-SiC

We report the abnormal behavior of longitudinal optical (LO) phonon in a silicon dioxide (SiO2) film on a 4H-SiC bulk epitaxial substrate using an attenuated total reflection (ATR) technique. The peak frequency of the LO phonon in the ATR spectrum was observed at around 1165 cm(-1) and red-shifted by approximately 92 cm(-1) relative to that at the grazing incidence (40 degrees), whereas the peak frequency of the transverse optical (TO) phonon in the ATR spectrum agreed well with that at the grazing incidence. Furthermore, the peak frequency of the TO phonon hardly depends on change in the incident angle and thickness, suggesting that the microstructure of the sample is homogeneous within a thickness of 100 nm. On the other hand, we found that the microstructure of the sample was inhomogeneous within a thickness less than 5 nm. Fourier transform infrared (FT-IR) spectroscopy provides us with a large amount of data on microstructures in the SiO2 films on a 4H-SiC substrate.

• 出版日期2013-5