New approach in Auger elemental relative sensitive factor calculation by using TEM-EDS analysis based on bi-layers of...

Area of Science:

• Materials Science and Engineering
• Surface Science
• Microelectronic Device Fabrication

Background:

• Wafer backside metallization (Ti-Ni-Au/Ag) is crucial for power device packaging, ensuring electrical contact.
• Nickel (Ni) diffusion to the surface of these layers can lead to oxidation and connection failures.
• Auger Electron Spectroscopy (AES) detects this Ni diffusion but often yields qualitative results due to inaccurate Elemental Relative Sensitive Factors (ERSF).

Purpose of the Study:

• To develop a more accurate method for determining ERSF for AES quantification in microelectronic device packaging.
• To overcome matrix effects that limit the accuracy of AES and Energy Dispersive X-ray Spectrometry (EDS).
• To establish a reliable standard for AES analysis of Ni diffusion in Ti-Ni-Ag stacks.

Main Methods:

• Utilized Transmission Electron Microscopy with Energy Dispersive X-ray Spectrometry (TEM-EDS) for quantitative analysis of Ni in Ag.
• Employed standard foils of Ag/Al and Ni/Al for initial method development.
• Validated the TEM-EDS quantification method on a Ti/Ni/Ag stack subjected to thermal stress to induce Ni migration.

Main Results:

• Demonstrated that TEM-EDS quantification of Ni in Ag can successfully determine accurate ERSF values.
• The validated method allowed for the creation of a characterized Ti/Ni/Ag sample serving as an AES standard.
• This standard enables more accurate ERSF calculation, improving AES quantification of Ni diffusion.

Conclusions:

• TEM-EDS offers a viable solution for accurate ERSF evaluation, mitigating matrix effects in AES quantification.
• The developed methodology facilitates the creation of reliable standards for analyzing critical failure mechanisms in microelectronic packaging.
• This advancement improves the reliability and quality control of power electronic devices.