Thin film thickness determination with neutron activation analysis

Area of Science:

• Materials Science
• Nuclear Physics
• Analytical Chemistry

Background:

• Accurate thin film thickness measurement is crucial for electronic and optical device performance.
• Traditional methods often require standard samples or complex calibration.
• Neutron activation analysis (NAA) offers a non-destructive technique for elemental analysis and film thickness determination.

Purpose of the Study:

• To develop and validate a novel NAA method for determining the thickness of various thin films.
• To assess the feasibility of NAA for tantalum pentoxide (Ta2O5), indium (In), and gold (Au) thin films.
• To complement NAA with optical transmission measurements for multi-layered film analysis.

Main Methods:

• Thin films of Ta2O5, In, and Au were deposited on glass, aluminum, and indium substrates.
• Samples were subjected to neutron irradiation.
• Gamma-ray emissions from radio-isotopes in the film and substrate were compared post-irradiation.
• Optical transmission measurements were performed on multi-layered Ta2O5 films.

Main Results:

• The NAA method successfully determined thin film thicknesses without the need for standard samples.
• Accurate thickness measurements were achieved for Ta2O5, In, and Au films on different substrates.
• Optical transmission measurements provided complementary data for individual layer densities in multi-layered films.

Conclusions:

• Neutron activation analysis is a reliable and standard-free method for thin film thickness determination.
• The combined NAA and optical transmission approach offers a comprehensive characterization of thin film properties.
• This technique has significant implications for quality control and research in thin film technology.