A new global optimization method for thin film thickness calculation is presented in this paper. A new adaptive simulated annealing (ASA) combining with genetic algorithm is brought out. Adding traditional genetic algorithm to simulated annealing process avoids the premature convergence problem and improves the ability of global searching effectively. Firstly it generates a new group of local optimums through genetic and mutation operation; then the solutions are accepted at a certain probability, and will be calculated respectively in ASA process as the initial solutions. At last conjugate gradient algorithm is utilized to search accurately and quickly. This new ASGA can effectively enhance the robustness of the algorithm and reduce the limitation of the searching area. The experimental results show that the proposed algorithm can calculate the thickness of single layer and 2-layer thin film within the range of 10nm to 1μ m and less than 4% calculation error.

Date Published: 20 November 2009
PDF: 9 pages
Proc. SPIE 7511, 2009 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Systems, 75111K (20 November 2009); doi: 10.1117/12.837924

Published in SPIE Proceedings Vol. 7511:
2009 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Systems
Shenghua Ye; Guangjun Zhang; Jun Ni, Editor(s)