Stress Characterization of the Interface Between Thermal Oxide and the 4H-SiC Epitaxial Layer Using Near-Field Optical Raman Microscopy. Issue 10 (October 2019)

• Record Type: Journal Article
• Authors: Yoshikawa, Masanobu; Fujita, Yasuhiko; Murakami, Masataka
• Is Part Of: Applied spectroscopy. Volume 73:Issue 10(2019)
• Page Start: 1193
• Page End: 1200
• Publication Date: 2019-10
• Subjects: Raman spectroscopy -- infrared spectroscopy -- near-field optical Raman microscopy -- stress characterization -- thermal oxide -- 4H-SiC; Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1177/0003702819856639
• Languages: English
• ISSNs: 0003-7028

Abstract

Stresses induced in the silicon carbide (SiC) epitaxial layer near the interface between thermal silicon oxide and 4H-SiC epitaxial substrate were measured using a near-field optical Raman microscope equipped with a hollow pyramid probe (aperture size: approximately 250 nm). The E2 phonon was observed to undergo a 0.17 cm −1 redshift owing to reduction in oxide-layer thickness from 300 nm to 0 nm; this result was compared against that obtained using a standard Raman microprobe sans the pyramidal probe. The result indicates that the epitaxial layer near the SiO2 –4H-SiC interface was maintained under a constant tensile stress of the order of 50 MPa. This agrees well with the result obtained using the finite element method (FEM). Based on results obtained using the said Raman microprobe and Fourier transform infrared (FT-IR) measurements, use of an inhomogeneity formation model at the SiO2 –4H-SiC interface has been proposed in this study.