Related Experiment Video
Updated: Feb 25, 2026
09:41
Using Laser Scanning Microscopy to Determine Electromigration in Molybdenum Disilicide
Published on: May 23, 2025
631
Interface morphology of Mo/Si multilayer systems with varying Mo layer thickness studied by EUV diffuse scattering
Optics Express
|August 10, 2017
Summary
We found a critical molybdenum (Mo) layer thickness that significantly impacts EUV mirror performance. This Mo thickness threshold affects reflectance and is influenced by interface polishing in Mo/Si/C multilayer mirrors.
Area of Science:
- Materials Science
- Optics
- Surface Science
Background:
- Mo/Si multilayer mirrors are crucial for extreme ultraviolet (EUV) applications.
- Understanding the influence of Mo layer thickness on mirror performance is essential for optimizing EUV optical systems.
- Interface roughness and material phase transitions significantly affect multilayer mirror properties.
Purpose of the Study:
- To investigate the effect of varying Mo layer thickness on the EUV reflectance of Mo/Si/C multilayer mirrors.
- To determine the relationship between Mo layer thickness, interface roughness, and EUV diffuse scattering.
- To identify a critical Mo layer thickness threshold that influences specular reflectance.
Main Methods:
- Utilized a combination of EUV and X-ray reflectivity measurements with near-normal incidence EUV diffuse scattering.
- Employed specular and diffuse intensity measurements to characterize interface roughness across the multilayer stack.
- Applied matrix methods for specular reflection and distorted-wave Born approximation for diffuse scattering.
- Introduced Markov-chain Monte Carlo methods for robust parameter confidence interval determination.
Main Results:
- Identified a threshold Mo layer thickness (1.7 nm to 3.05 nm range) where EUV specular reflectance exhibits a local minimum.
- Observed a distinct increase in diffuse scatter correlated with the reflectance minimum, indicating enhanced interface roughness.
- Attributed the observed phenomena to an amorphous-to-crystallization transition in the Mo layer, with polishing altering this threshold.
Conclusions:
- Mo layer thickness critically influences EUV mirror reflectance and scattering properties.
- A specific Mo thickness threshold triggers an amorphous-to-crystallization transition, impacting mirror performance.
- Interface polishing modifies the critical Mo thickness, offering a pathway to tune mirror characteristics.
