Characterization of micro structure through hybrid interference and phase determination in broadband light...

Area of Science:

• Optical metrology
• Surface characterization
• Interferometric techniques

Background:

• Broadband light interferometry is a key technique for surface profiling.
• Conventional methods using light irradiance for zero fringe order detection suffer from instability due to intensity fluctuations and external light.
• This instability limits accuracy and reliability in surface measurement systems.

Purpose of the Study:

• To develop a hybrid interferometric technique for robust surface profiling.
• To suppress light instability and improve the accuracy of zero optical path difference determination.
• To enhance the sensitivity, robustness, and stability of interferometric surface measurement systems.

Main Methods:

• A hybrid technique combining light intensity and spectral modulation was developed.
• Phase evaluation at each pixel was employed for high vertical resolution micro-structure characterization.
• Simulations and experimental verification on a micro-dome structure were performed.

Main Results:

• The hybrid method effectively suppresses light instability.
• High vertical resolution was achieved for micro-structure characterization.
• The method demonstrated improved sensitivity, robustness, and stability compared to conventional techniques.

Conclusions:

• The proposed hybrid interferometry method offers a significant improvement over intensity-based techniques.
• It is particularly promising for surface profiling in complex and unstable environments.
• This technique enhances the reliability and precision of micro-structure characterization.