In Situ Analyses of Surface-Layer Composition of CxNy Thin Films Using Methods Based on Penning Ionization...

Area of Science:

• Materials Science
• Plasma Physics
• Surface Chemistry

Background:

• Carbon nitride (CNx) materials exhibit valuable tribological, mechanical, and optical properties.
• These properties are critically dependent on the nitrogen-to-carbon (N/C) ratio within the film.
• Precise control over the N/C ratio during synthesis is essential for optimizing CNx material performance.

Purpose of the Study:

• To develop and validate a plasma-electron spectroscopy method for in-situ control of the N/C ratio in CNx films.
• To enable real-time monitoring and adjustment of film composition during the plasma sputtering process.
• To establish a method for on-line inspection of CNx film surfaces without sample removal.

Main Methods:

• Utilized plasma-electron spectroscopy based on Penning ionization analysis.
• Employed a single Langmuir probe to determine the electron energy distribution function.
• Conducted plasma sputtering using a pulsed-periodic glow discharge with N2:CH4:He gas mixtures.
• Varied CH4 concentrations (2-8%), He concentrations (80-90%), gas pressure (1-10 Torr), and current (10-50 mA).

Main Results:

• Demonstrated the capability of the developed method to extract information about the surface layer composition of CNx films.
• Successfully established an on-line inspection capability for CNx films during the sputtering process.
• Confirmed that the N/C ratio can be effectively controlled in-situ.

Conclusions:

• The developed plasma-electron spectroscopy method provides an effective means for in-situ control of the N/C ratio in sputtered CNx films.
• This on-line inspection capability allows for real-time monitoring and optimization of film composition.
• The technique facilitates the production of high-quality CNx materials with tailored properties.