Roughness parameters for standard description of surface nanoarchitecture

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Metallic thin films are crucial in various technological applications.
• Understanding their nanoarchitecture and surface roughness is essential for optimizing performance.
• Magnetron sputtering is a common technique for preparing these films.

Purpose of the Study:

• To analyze the nanoarchitecture and surface roughness of metallic thin films.
• To determine topographical statistics that best describe nanoarchitecture.
• To propose a new standard for surface nanoarchitecture characterization.

Main Methods:

• Prepared titanium and silver thin films of varying thicknesses (3 nm, 12 nm, 150 nm) using magnetron sputtering.
• Performed atomic force microscopy (AFM) scans on 1 μm × 1 μm areas.
• Calculated seven statistical topographical parameters, including R(a), R(q), R(skw), R(sa), and R(pc).

Main Results:

• The 150-nm titanium film exhibited the highest average roughness (R(a) = 2.63 nm).
• Coating silver films on 150-nm titanium increased roughness; 3-nm and 150-nm silver films showed R(a) ≈ 4.96 nm and 4.65 nm, respectively.
• Skewness (R(skw)), surface area increase (R(sa)), and peak counts (R(pc)), along with R(a) and R(q), best characterized the surface architecture.

Conclusions:

• A combination of five roughness parameters (R(a), R(q), R(skw), R(sa), R(pc)) provides a comprehensive description of surface nanoarchitecture.
• These five parameters are proposed as a new standard for characterizing metallic thin film surfaces.
• This standardized approach will enhance the comparability and understanding of thin film properties.