Surface resistivity estimation by scanning surface potential microscopy

Area of Science:

• Materials Science
• Surface Science
• Thin Film Technology

Background:

• Nickel (Ni) thin films are crucial in various electronic applications.
• Understanding their surface properties, like resistivity, is essential for device performance.
• Sputter deposition is a common technique for creating thin films.

Purpose of the Study:

• To investigate the morphology and surface resistivity of nickel thin films.
• To compare surface resistivity measurements obtained by scanning surface potential microscopy (SSPM) with standard four-point probe methods.
• To analyze the effect of deposition atmosphere (argon vs. nitrogen) on Ni thin film properties.

Main Methods:

• Sputter deposition of 600 nm nickel films on glass substrates.
• Atmospheric control during deposition: argon or varying partial pressures of nitrogen (1.3 x 10(-4) or 4 x 10(-4) mbar).
• Characterization using Atomic Force Microscopy (AFM) for morphology and Scanning Surface Potential Microscopy (SSPM) for surface resistivity estimation, considering surface roughness.

Main Results:

• Nickel thin films were successfully deposited under different atmospheric conditions.
• SSPM provided reliable surface resistivity estimations for the Ni thin films.
• Surface resistivity values obtained via SSPM showed good agreement with four-point probe measurements across all investigated samples.
• Morphological analysis using AFM provided insights into surface topography.

Conclusions:

• Scanning Surface Potential Microscopy (SSPM) is a viable technique for estimating the surface resistivity of nickel thin films.
• The results validate SSPM's accuracy by demonstrating good correlation with traditional four-point probe measurements.
• This study contributes to the understanding of Ni thin film characterization, particularly concerning surface electrical properties.