A speckle shearing interferometric system is proposed for real-time inspecting sub-surface defects of unpolished silicon wafer. Under dynamic thermal loading, derivative distribution of out-of-plane displacement along a shear direction is measured and homogeneity and regularity of the distribution is indicator of whether impurities or voids exist under the wafer surface. During a continuous thermal stressing, a sequence of speckle patterns are obtained and phase analysis is implemented in time domain. In this paper, the validity of the method for non-destructive testing of sub-surface defects of silicon wafers has been demonstrated.

Date Published: 12 April 2005
PDF: 6 pages
Proc. SPIE 5852, Third International Conference on Experimental Mechanics and Third Conference of the Asian Committee on Experimental Mechanics, (12 April 2005); doi: 10.1117/12.621673

Published in SPIE Proceedings Vol. 5852:
Third International Conference on Experimental Mechanics and Third Conference of the Asian Committee on Experimental Mechanics
Chenggen Quan; Fook Siong Chau; Anand Asundi; Brian Stephen Wong; Chwee Teck Lim, Editor(s)