Advanced Technologies for Estimation of Nonlinear Ultrasonic Parameter
This paper proposes an advanced signal processing technique for the precise estimation of a nonlinear ultrasonic parameter, based on power spectral and bispectral analysis. The power spectrum and bispectrum estimation of the pulse-like ultrasonic signal used in the commercial SAM (scanning acoustic microscopy) equipment is especially considered in this study. The usefulness of the proposed estimation is confirmed by experiments for a Newton ring with a continuous air gap and a real semiconductor sample with local delaminations. The results show that the nonlinear parameter obtained by the proposed method had a good correlation with the delamination.
Soon-Bok Lee and Yun-Jae Kim
K. Y. Jhang, K. Sasaki, J. Ha, H. Tanaka, "Advanced Technologies for Estimation of Nonlinear Ultrasonic Parameter", Key Engineering Materials, Vols. 326-328, pp. 673-676, 2006