基片与不同方位多形态缺陷粒子的复合光散射特性分析

结合光学表面无损检测工艺实际情况,给出基片与镶嵌及掩埋的球体/回转椭球体缺陷粒子的散射特性分析。针对基片与缺陷粒子的半空间问题,结合时域有限差分方法使用广义完全匹配吸收层(GPML),结合三波技术引入激励源,给出了相应的连接边界条件,并将互易性定理应用到近远场外推中,使过程简化。数值计算给出了镶嵌及掩埋的球体/回转椭球体缺陷粒子的散射场的角分布。结果显示:镶嵌比掩埋的缺陷粒子受粒子尺寸的影响更明显。在大散射角下,缺陷粒子的位置因素带来的贡献较大。粒子分别掩埋或镶嵌于基片时,在-10°、30°、70°附近的球体粒子和回转椭球体粒子的微分散射截面(DSCS)差别较大。在基片无损检测工程中可以通过对特定角度散射场的测量定标诊断出缺陷的方位和形态。

Analysis of Composite Light Scattering Properties Between Wafers and Many Shapes of Particles with Different Positions

Combing the practical situation of nondestructive examination, the analysis of composite light scattering properties between wafers and many shapes of particles with different positions is shown. Against the half-space problem about wafer and defect particles, the generalized perfectly matched layer (GPML) can work very well. The boundary consistency conditions are given by three waves method. The reciprocity theorem is applied to near-far field extrapolation. The angle distribution of sphere or ellipsoidal defect particles are given. The results show that the influence of inlaid particles on size is more obvious than inside ones. In the large scattering angle, the contribution of the position factor is much more. In the angle of -10°, 30°, 70°, the differential scattering cross section (DSCS) difference about sphere and ellipsoidal particles is more obvious. In the wafer′s nondestructive examination project, the defect position and shape are diagnosed by the scattering field of specific angles.