基片及其上方回转椭球粒子极化光散射

基于BV理论建立基片及其上方回转椭球粒子的复合散射模型,通过矢量球谐函数展开,对散射过程进行了分析,对散射场及微分散射截面详细求解,并给出了数值计算结果,与离散源方法做了比较,同时退化为球粒子与扩展Mie理论做了比较,说明了此方法的有效性。并详细讨论分析了微分散射截面随不同入射角,散射角,回转椭球粒子的尺寸、长短轴比例,距基片的距离,介电常数,粒子取向角的变化关系。结果表明:同一散射角下入射角越大,其微分散射截面越大;粒子尺寸越大,相互作用越大,其微分散射截面越大;长短轴比例越大,其微分散射截面越小;距离基片的距离越大,微分散射截面越大;微分散射截面的变化主要依赖于相对介电常数实部、虚部数值较大的一方,并且随粒子取向角的增大而增大。

Polarized light scattering from a spheroid particle on or near a wafer

Taking the advantage of the BV theorem, a scattering model is established for the polarized light scattering from a spheroid particle on or near a wafer. The scattering process is analysed and the scattering coefficients are derived through expanding vector spherical harmonic functions. The variation of differential scattering cross section（DSCS） of a spheroid particle with scattering angle is calculated, which is compared with the results of discreter sources method and extended Mie method. The results are coincident, proving the validity of the method. The variations of DSCS are discussed with incident angle, scattering angle, spheroid particle size, axial ratio, the distance of the particle from the wafer, dielectric constant, and particle azimuth angle. The result shows that with th