Analysis of zenith angle influence on the scattering properties by the spheroid particle upon wafer

The influence of zenith angle on the scattering properties by the spheroid particle upon wafer is discussed in this paper. Taking the advantage of the Bobbert-Vlieger (BV) theorem, the scattering model between wafers and spheroid particles is established. The scattering process is analyzed and the scattering coefficients are derived by using of the vector spherical harmonic function. The differential scattering cross section (DSCS) of a spheroid particle upon the wafer is calculated which is compared with the Discrete Sources Method (DSM) proved the validity of the method and the influences of the zenith angle on the DSCS are analyzed numerically in details. The results show that the larger the incident angle and the azimuth angle, the larger the DSCS, which provide strong theoretical foundation to the nondestructive detector engineer.