Spatially resolved Raman piezospectroscopy for nondestructive evaluation of residual stress in β-Ga2O3 films. (2nd March 2023)

• Record Type: Journal Article
• Authors: Hara, Yasuaki; Zhu, Wenliang; Deng, Gaofeng; Marin, Elia; Guo, Qixin; Pezzotti, Giuseppe
• Is Part Of: Journal of physics. Volume 56:Number 12(2023)
• Publication Date: 2023-03-02
• Subjects: Raman -- piezospectroscopy -- residual stress -- Ga2O3; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/acbbdb
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: In this paper, the piezospectroscopic effect for β -Ga2 O3, i.e. the spectral band shift in response to strain/stress, has been calibrated by the indentation method using spatially resolved Raman spectroscopy for quantitative stress evaluation of Ga2 O3 devices, taking advantage of the crack-tip tensile stress field and the spatial probe deconvolution. A series of Vickers indentation prints were introduced on (010) and ( 2 ˉ 01 ) Ga2 O3 single crystals, and the relationships between observed band shifts and residual stresses were clarified to determine the phonon deformation potentials of the Raman bands. Accordingly, a quantitative analysis of the residual stress field in a Ga2 O3 thin film grown on (0001) sapphire by plasma-assisted pulsed laser deposition, which revealed the presence of a gradient of incompletely released stress in the depth direction of the film, is shown as an example.