| dc.description.abstract | This study proposes a novel approach that combines ellipsometry techniques with spectral reflection measurements to analyze the characteristics of optical thin films, including thickness and refractive index. To ensure measurement accuracy, error analysis is conducted through simulations before actual thin film measurements are performed. This practice aids in promptly identifying potential issues during the experimental process and taking corrective measures to enhance overall accuracy.
Following the simulation analysis, further prediction of error thresholds for various parameters is carried out. For instance, within the anticipated range of errors, such as thickness deviations below 2 nanometers and refractive index errors less than 0.5%, the absolute errors of polarizing angles and analyzer angles in actual thin film measurements need to be less than 0.1 degrees, while the absolute error of the incident angle should be less than 0.2 degrees. These error thresholds ensure that the results obtained during the experimental process maintain a certain level of accuracy within acceptable limits.
To achieve optimal fitting effects, this study employs a genetic algorithm to identify the global best solution within the entire parameter space. Additionally, the use of the RAE architecture and a four-point measurement method facilitates rapid system measurement and computation. These choices not only expedite the measurement process but also simplify operations.
Stability tests and standard sample assessments successfully validate the stability and accuracy of the system. With decreasing errors and program optimization, the measured thickness of ultra-thin films using this system exhibits absolute errors consistently below 0.8 nanometers, while the percentage error in refractive index remains below 1%, showcasing system stability and precision once again.
In summary, the method and system presented in this study provide a potent tool for analyzing the characteristics of optical thin films. By combining ellipsometry techniques with spectral reflection measurements and guided by simulation analysis, the research effectively achieves high-precision measurements of sub-nanometer-level thickness. | en_US |