Microinterferometry: Three-Dimensional Reconstruction of Surface Microtopography for Thin-Film and Wetting Studies by...

Area of Science:

• Microscopy and Imaging
• Surface Science
• Thin Film Analysis

Background:

• Reflection interference contrast microscopy (RICM) is used for studying stratified films on substrates.
• Existing RICM theories have limitations in analyzing nonplanar film surfaces.

Purpose of the Study:

• To present an improved RICM theory for stratified films on planar substrates.
• To propose a new theoretical approach for analyzing the surface profile of nonplanar films.
• To validate the new approach using simulations and experimental data.

Main Methods:

• Developed an improved theoretical model for RICM image formation.
• Proposed a new analytical method for nonplanar film surface profiling.
• Utilized simulations to study the impact of illumination aperture and interface shape.
• Analyzed fringe patterns from wedge-shaped liquid films and spherical probes.

Main Results:

• Demonstrated the validity of the new approach for nonplanar films.
• Identified angular and curvature correction terms for accurate topographic reconstruction.
• Showcased how interface slope affects fringe pattern intensity and amplitude decay.
• Quantified the influence of finite-aperture illumination on RICM images.

Conclusions:

• The improved RICM theory and new analytical approach enhance the structural study of stratified films.
• Accurate microscopic topography reconstruction is achievable for both planar and nonplanar surfaces.
• Understanding fringe pattern variations is crucial for interpreting RICM data from complex interfaces.