双层膜椭偏数据处理的新算法

New algorithm to the ellipsometric data inversion of double films

为了准确测量双层透明膜,有效地结合了模拟退火法和单纯形法的优点,提出一种模拟退火-单纯形混合算法来处理双层透明膜的椭偏数据。在单波长测量时,仅测量1组椭偏参量,可以求解双层透明膜任意两个参量;测量两组以上椭偏参量,可以同时反演双层透明膜4个参量,求解薄膜折射率和厚度精度分别达到0.0002和0.07nm。结果表明,模拟退火-单纯形混合算法反演双层透明膜参量是可行和可靠的,且有较强的样品适应性。该算法适合于单波长椭偏仪对双层及多层膜的反演及实际测量。

In order to measure the optical parameters of double layer films accurately, with an effective combination of advantages of the simulated annealing algorithm and the simplex algorithm, a simulated annealing-simplex hybrid algorithm was presented to deal with the ellipsometric data inversion of double layer films. In experiments of single wavelength measurement, any two optical parameters of double layer films can be extracted with a measurement of only one group of ellipsometric parameters. Likewise, two or more groups of known ellipsometric parameters can determine four optical parameters simultaneously. And the measured accuracies of refractive index and thickness of films are 0. 0002 and 0. 07nm respectively. Results of actual measurements show that using the hybrid algorithm to obtain the optical parameters of double layer film is feasible and reliable, and has strong flexibility for various samples. The algorithm is suitable to inversion and actual measurement of double laver films and multi-laver films bv sinale wavelength ellipsometer.