Test method of SiC crystal phonon anisotropy based on polarized Raman spectroscopy

Abstract

The invention relates to a test method of SiC crystal phonon anisotropy based on polarized Raman spectroscopy, wherein the test method includes the following steps: (1) processing SiC crystals respectively, to obtain a-face, c-face and m-face samples, and polishing; (2) adding a semi-wave sheet in an incident light path of a Raman spectrometer, and adding a polarizing sheet in a back scattering light path; (3) fixing the direction of the polarizing sheet, rotating the semi-wave sheet to change the relative direction of the incident polarized light to the scattering polarized light, and testinga polarized Raman spectrum; (4) fitting peaks of different phonon modes, to obtain the Raman intensities of a plane mode E1, a plane mode E2 and an axial mode A1; (5) carrying out normalization treatment law of the Raman peak intensities of the plane mode E1, the plane mode E2 and the axial mode A1; and (6) obtaining anisotropy of different anisotropic phonon modes. By optimizing the test parameters, the anisotropy of the phonons in different polarity faces of the SiC crystals is effectively characterized.

Description

technical field [0001] The invention relates to a method for testing phonon anisotropy of SiC crystals based on polarized Raman spectroscopy, in particular to a method for testing phonon anisotropy of SiC crystals with different polarities based on polarized Raman spectroscopy, which belongs to microelectronics and optoelectronics field of materials technology. Background technique [0002] As a third-generation semiconductor, silicon carbide has the advantages of large bandgap, high thermal conductivity, high critical breakdown field strength, high carrier saturation migration efficiency, and low dielectric constant. It is used in high-temperature, high-frequency, and high-power devices. It has great application space. Due to the different stacking forms, SiC has more than 200 crystal forms, including 4H, 6H, 15R and so on. At present, the preparation and performance of semiconductor materials have become the key factors that determine the performance and development of d...

AI Technical Summary

Problems solved by technology

However, this study did not explore the law of phonon anisotropy in depth, and in this method, the phase difference between tensor elements has an important influence on the properties of phonon mode strength, and the phase difference between tensor elements is difficult to obtain accurately, so the phonon Anisotropy law cannot be calculated

[0006] In general, at present, the anisotropy of phonons in SiC crystals cannot be directly observed and characterized, and the related research on the anisotropy of phonons on different polar planes is still blank. Therefore, a direct and accurate method is invented. Metrics are important

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